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On lens hype... and a bargain vintage set
I write a lot of blog articles in reaction to external stimuli, even if this is not immediately obvious. People ask me questions in the pub or on Facebook. I need to explain something in detail to my students. A topic required documentation before I myself forget what I already know.  This post is in reaction to those YouTube videos fronted by some egotistical talking head who pretends to be a photography expert, discovering, as if struck with a bolt from above, the merits of some old system. You know the type. They use phrases like "game-changer" and "GOAT". This tendency leads to particular lenses shooting up in price beyond all reason. Let me provide a few examples of over-hyped gear, before suggesting a set of vintage lenses that won't kill your bank account.  Schweppes with Pentax-A 28/2.8 Overhyped and over-pricedCarl Zeiss Jena lenses were once cheap as chips. They were made using fairly ordinary optics with poor quality control in East Germany. The lubrication dries out over time, making apertures stick. Similarly the focus goes tight. And parts fail. In terms of optics you will experience softness, poor corner resolution, busy bokeh, and various aberrations. Somehow these deficiencies become positive features to internet pundits. I am not saying that these lenses should be avoided. The look of a Jena Pancolar 50/1.8 (to take one example) might be useful as a tool in your lens box. But given their age, any Jena sample you find will likely need thorough servicing, at a cost of €100-200 plus shipping. So even if the lens itself was free, this prices them well outside their value. But they aren't free. Prices range up to €600 for some Jenas, which is ridiculous.  A second example is the lowly Zuiko AUTO-S 40mm F2, produced for Olympus SLRs from 1984 to 1994. This is a cute lens but has certain practical disadvantages when miniaturised to this extreme. As many reviewers note, the tiny aperture ring on the front of the lens is difficult to use. All reports concur that the lens has decidedly average image quality. Nonetheless, this item currently costs €1200. But that's nothing. Three years ago Mike Johnston reported one sold for $3800! That is peak hype when one considers the alternative: the Olympus Zuiko 50mm F1.8 is common as muck and optically superior. It's still small but more usable. Price? €50. Just today I watched a YouTube video that pronounced that Olympus lenses were the greatest of all time. Sure, they are nice. I appreciate the small profile of the original series, even if this design mandate was abandoned for large fast lenses later in the OM mount lifespan. For a while I was even sourcing lenses for the Pen F half-frame camera... also now getting hyped (sigh). Earlier this week I watched some professorial type (peering out from over the top of his glasses) claiming that several ancient M42 lenses were "razor sharp". No, they aren't. Contemporary lenses are, in almost all cases, far "sharper" (depending on what you really mean by that term) than those designed before CAD/CAM and new materials revolutionised the optics industry. There's no comparison. But we don't buy vintage lenses because we want the sharpest possible image. We buy them for their unique rendering properties. The same dude says just as much in other videos but needs to continue feeding the hype train, I suppose.  Limerick Junction with Pentax-A 28/2.8 A bargain vintage set It's only a matter of time before someone "discovers" that Asahi made excellent Pentax lenses for their K-mount, with better IQ (in most cases) than the M42 lenses they previously marketed under the brand Takumar. Those Taks are already hyped to death. Naturally.  Since I don't make hype videos, I will just drop this information here on my obscure little blog so that you special readers can benefit.  I can recommend four primes to cover different focal lengths. Many of you might only need the 28mm and 50mm, but people have different shooting styles. All these lenses are quite compact, have a wonderful metal build (no plastics) and provide a consistent rendering that is free of gimmicks. The initial Pentax K series had some excellent optics, but the best of that series sell for a lot more than the second M series. With this line the lenses became significantly more compact, which is something many photographers (myself included) can appreciate. The SMC Pentax-M 28/2.8 (€100) is only 37mm long and 170g. It focuses to 30cm and takes a 49mm filter. SMC Pentax-M 35/2.8 (€100) is identical in all particulars but covers an angle of view preferred by street photographers.  The "normal" SMC Pentax-M 50/1.7 (€50) is even smaller at length 31mm and a similar 185g. Focusing to a close 45cm it too has a 49mm filter thread. If you need something longer, for portraits perhaps, the SMC Pentax-M 135/3.5 (€60) is still only 270g. The close focus is 1.5m (not close at all) and the filter is the larger 52mm. zone of cats with Pentax-M 50/1.7 One note when you come to purchase. The third "A" series of Pentax lenses were, in many cases, optically identical to their M predecessors. This is true of the 28mm and 35mm models that I've specified here. Normally the A series are more expensive, since they have automatic aperture control when used on Pentax SLRs. Adapting for mirrorless digital cameras, this makes no difference. So you can add these models to your search list and maybe find an even better specimen.I have never bought a used Pentax lens that needed servicing or was in any way less than ideal. These were built to last! Check listings carefully and you should have equal luck.  I've illustrated this article with photos taken on two of the lenses mentioned, so you can check out the colour rendering, bokeh, and other aspects of the image. Please note that internet compression will make these appear blurry in comparison to the originals. In fact, all these shots are suitably sharp and otherwise beautiful. They have a subtle vintage look that is compelling without being attention-grabbing. (As always, click on an image to get a larger version.) I should note that zone of cats has been colour-processed to get a more muted look. All were shot on the very wonderful Panasonic Lumix S5.So, no lens hype, no goats to be seen. Just a wonderful set of affordable lenses at a bargain price. For now, anyway!

Field recorders in 2024
I am a trained audio engineer who wrote extensively on field recorders over many years. You can access these articles from my field recording landing page. Two years ago I provided a detailed summary of the state of the art in portable field recording devices. This article brings my research up to date for 2024. First, download the PDF that charts every available portable field recorder priced at under a grand. I also include a table of defunct models for historical comparison. Marketing and the numbers problem In the mass market numbers sell but quality doesn't. Case in point: the vast majority of untrained recordists now believe that a 32-bit PCM encoding input stage will give them a better recording. While 32 bits is convenient, it's not an instant panacea. Indeed, this feature has certain disadvantages. Being unable to manually gain stage means it's difficult to compare recordings made at different times for absolute volume and noise floor levels. The marketing obsession with 32-bit obscures more important factors. First among these is pre-amplifier quality. This is measured using equivalent input noise (EIN). Newer recorders do not necessarily provide better pre-amps.  An interesting data point is provided by Sony Minidisc recorders. The final line of these hand-held devices, released way back in 2004, was branded Hi-MD. These models finally allowed uncompressed recording after years of Sony's stubborn insistence on their own compression standard. Remarkably, Hi-MD recorders had better microphone pre-amps than most gear today. Despite the input encoding being "only" 16-bit, they achieved -124 dBu EIN. This is close to Sound Devices quality! It's remarkable that many contemporary 24-bit and 32-bit recorders don't match the quality of old 16-bit Minidisc technology. This is why certain older recorders, for example the Sony PCM-D100, are still prized. But it's difficult to recommend purchasing a discontinued unit with inflated used prices. Such a device is likely to have a short working life and there will be no support from the manufacturer. The state of the art? Many inexpensive recorders are fine for recording a band rehearsal, an interview, or other sources with high signal levels. The popular Zoom H series are feature-rich but the EIN maxes out at -120 dBu. This is not ideal for field recordings of quiet sources. Instead I recommend the Zoom F series which have 8 dB less noise... a significant difference! (Check out my comparison table for other options).While such recorders provide both incredible features and excellent recording quality for the money, they lack the long-term customer support that is characteristic of professional gear. That category remains the domain of Nagra, Sonosax, and the Sound Devices 700 series. These cost big money for a reason. If your career depends on a recording, there's no substitute. But I omitted these options from my comparison table, since if you're reading this, you likely aren't in that market! The Sound Devices MixPre series exists in a middle ground, compromising the brand's name in order to compete on price. The noise figures are excellent but the Zoom F8 provides a higher track count, more features, and dual card recording. Summary Once upon a time we could buy pocket-sized audio recorders of good quality. I have made many published recordings using my Olympus LS-10 and the Sony PCM-M10 was also excellent. In 2024 all available models in this smaller form factor are plagued with inferior pre-amps. One exception is the Zoom F3... though this has an annoying interface and lacks the convenience of plug-in-power.If you are happy with a larger device, several models are suitable for field recording of quiet sources. Buy based on the features you need and the EIN figure. Ignore other marketing hype. 32-bit recording won't give you better results. Learning your craft will. That's the lesson I wish to drive home in 2024.NoteI significantly rewrote this article two days after initial posting, to make my points clearer and provide the updated recorder table.

Where is the perfect EDC bag?
For years I have been on the search for the perfect every-day carry (EDC) bag for a camera plus one lens and a few small personal items (e.g. headphones). I will explain my goals and describe the bags that I currently own. Maybe you can help me find something better? Constraints 1. SizeThe baggage allowances for airlines vary, so I have combined the limitations of several carriers that I use. This results in a maximum dimensions of 33 x 25 x 12 cm. While this might be a bit too large for an EDC, it's a useful target. In order to safely carry a camera without adverse pressure, the width must be at least 10cm. This eliminates most smaller bags from consideration. 2. Form factorMost items sold as courier bags or cross-shoulder bags are wider than they are high. This means that they bang against the side of the body when moving. I prefer a bag higher than it is wide, so that it fits on the hip and can be swung back slightly on my body. Then it is almost invisible and more comfortable. 3. Padding and weightMany items sold as camera bags are extensively padded. This make sense for the intended use, but results in a significant reduction in interior volume, which is not ideal as a carry-on item. Weight too is a factor for a comfortable EDC. At the other extreme, a floppy bag is too dangerous for camera gear. A compromise is required. 4. Pockets and zipsMany bags sold for business or student use have far too many internal and external pockets, again reducing the effective volume. The profusion of zips and fasteners increase the chance of scratching gear. I am OK with maybe one zippered pocket, preferably on the outside of the main compartment. 5. WaterproofingMany casual bags have a top flap that doesn't cover the opening and are hence useless in rain. I would prefer a totally waterproof bag, but will make do with less, so long as the main compartment is sealed.6. StyleI don't want my bag to scream "expensive camera" nor do I wish to look like an escapee from a branding factory. My attempts to date The following are the bags I own. Not pictured is a Crumpler Pretty Boy 7500 XXXL which is 34 x 24 x 18cm and hence too wide for airlines, also being over-padded. On the left is a bag from the Mountain Equipment Co-Op (now Company) in Toronto. It is 30 x 22 x 10cm and can be carried vertically, with a top opening for conveniently grabbing a camera. It has one internal zippered pocket where I keep lens wipes, etc. This is the closest to my ideal bag at the moment. Naturally there's nothing like this available from this firm today! Next is a rather generic Quadra canvas bag that I bought ages ago. (The model is either QV003 or QD662 but in any case it's no longer in production.) This bag has lasted through every adversity, though the velcro fasteners long ago stopped working. It's a bit floppy, so I used to make cardboard inserts as additional structure. Though it's too small at 24 x 22 x 11 cm to optimise carry-on capacity, I pack this as a bag useful when I arrive at my destination. Though comfortable it lets the rain in. My most recent purchase was an attempt to find a larger version of that bag. The Quadra Vintage Canvas Messenger Sahara (QD611) is 34 x 29 x 10 cm (8L and 480g). It is ridiculously floppy and has an annoying metal fastener that jangles. It also turns out to be larger than the minimal personal item dimensions (though could likely pass inspection). A reinforced version of this bag would be better... except that the design also lets in water. And so... I have looked at most every available bag (online and in person) in an effort to find something slightly larger than the grey canvas bag, with a sealed top, and water resistant. If you have any suggestions, please do let me know in the comments.

Which SD card?
SD memory cards are used for everything from mobile phones, field recorders, still cameras, and video cameras. The most common question is... which SD card should I buy? This article will decode all of the designations and provide simple answers. Card type and capacity First, decide on how much storage you need, based on what your device will support. This will dictate the Card Type, since each has a certain maximum capacity: SDSC (1999) = 2 GB SDHC (2006) = 32 GB SDXC (2009) = 2 TB SDUC (2018) = 128 TB For example, I might want a 256 GB card for my video camera to enable long recording times at high bit rates. So I choose an SDXC. I check my camera manual (or online spec sheet) and sure enough SDXC is supported. I am good to go! Bus speed The earliest SDSC supported only Standard speed. Since then we've had a choice of buses, each of which indicates (but does not guarantee) maximum read/write speeds.  Standard: 12.5 MB/s High-speed: 25 MB/s UHS-I: 50 MB/s or 104 MB/s half-duplex UHS-II: 156 MB/s or 312 MB/s half-duplex UHS-III: 312 MB/s or 624 MB/s full-duplex You can often ignore these numbers because easier labels have been introduced.  Speed Class Ratings Speed Class Rating guarantees minimum sustained write speed. These replace the older "x" measures. Class 2 = 2 MB/s Class 4 = 4 MB/s Class 6 = 6 MB/s Class 10 = 10 MB/s Video Speed Class similarly indicates minimum write performance, but is specifically aimed at video usage, as you might imagine from the name! There are 8 bits to a byte, but the numbers are rounded down for safety. V6 is the same as the old Class 6 and V10 is Class 10, but the rates go up from there.  V6 = 6 MB/s (maximum bitrate 45 Mbit/s) V10 = 10 MB/s (75 Mbit/s) V30 = 30 MB/s (220 Mbit/s) V60 = 60 MB/s (460 Mbit/s) V90 = 90 MB/s (700 Mbit/s) You might also see the older UHS Speed Class on labelling. It's less useful, and you can ignore it. But for completeness: U1 is equivalent to V10 U3 is equivalent to V30 Though photography is not as demanding of storage media, you might need a faster card than you think. Burst shooting is sometimes accomplished at 30 frames per second, which is basically identical to shooting video. Note the write speed you'll need by reading your camera manual. Videographers should note the highest resolution video mode you will record, along with the corresponding bit rate. If you are using a Lumix S, you can use my handy charts to look up these numbers.  What brand? Several brands tend to be recommended, but there's always the possibility of getting a lemon. Lexar Professional, Transcend, and SanDisk are popular choices. But be sure to buy from a popular retailer, since auction sites (including eBay) and grey market sources might well be pawning off counterfeit cards. An example Let's consider the card pictured at the top of this article. I purchased this in order to get the most from a Lumix S-5, which records video at up to 200 Mbit/s. Was this a good decision? First, we can ignore the text that says "1800x" and "U3" since these are deprecated specifications. We can ignore SDXC once we have confirmed that our device supports that card type.  What is most important is the V60 designation. This indicates a maximum video record rate of 460 Mbit/s which is more than enough. In fact we could have bought a V30 card... but at the time of purchase there was a sale that made the cost only incremental between the two speeds.  As for the capacity, 256 GB is ridiculously large. This reduces the need to erase work regularly. Since my camera has two SD slots, I never erase the second card, effectively using this as a portable backup. 

Comparing vintage 28mm lenses
I love the 28mm field of view and wanted to update my insights now that I've returned to using a full-frame camera. Here I will compare five different 28mm film-era lenses, namely:smc PENTAX 1:2 28mm (1976) Carl Zeiss Distagon T* 28mm f/2.8 (1978) for Contax-Yashica mountKino Precision Kiron 28mm f/2 MC (1981)Vivitar 28mm 1:2.0 MC Close Focus (1983) made by KomineSMC PENTAX-A 28mm f/2.8 (1984)This article is the result of months of work shooting in real-world scenarios and staged tests. Hopefully of interest to other photographers... like you! Introduction I have a history of dedication to 28mm focal length lenses. Back when I was using a Pentax DSLR with an APS-C sensor, 28mm corresponded to a useful "perfect normal" field of view. There was a plethora of such lenses available for the K-mount. A series of random bargain-basement purchases alerted me to those marketed under the Vivitar brand name. With the help of photographers on the Pentax Forum, I began compiling information. The result was The Great Vivitar 28mm Bestiary, first published in 2009. This compendium grew to include 38 variants... and that's only counting those Vivitar lenses compatible with Pentax! There are even more models for other mounts. Today I use a full-frame camera on which a 28mm focal length renders a 74° angle of view. This wide angle maintains a naturalistic image without perspective distortion calling attention to itself as a "special effect". Of course many wonderful photographs can be taken with much wider lenses, but these are of niche interest... to me at least! Whereas 28mm is a useful focal length every day. I find it strange that in the contemporary digital market, manufacturers commonly produce a 24mm prime for their systems, but many brands (including Panasonic Lumix) do not provide the classic 28mm focal. Of course any number of zoom lenses can be pressed into service. But I prefer the ergonomics of vintage primes with aperture dials. The experience is simply more satisfying.  Circa 2008 I leveraged my growing collection of 28mm lenses to publish test articles on this blog (itemised in an appendix below). But lenses that might perform admirably on a smaller sensor face a greater challenge on full-frame, where the entire image circle is used. So I decided to update my aged APS-C sensor tests. This has taken some work! The Lenses In this section I will provide an overview of the lenses. For convenience I've named these the Pentax Distagon, Zeiss Distagon, Pentax A, Vivitar by Komine, and Kino by Kiron. This saves you reading the full name each time.  Pentax Distagon The Carl Zeiss Distagon T* 28mm f/2.0 was released for the Contax-Yashica mount in late 1975. Designer Erhard Glatzel collaborated with Pentax, who were planning the launch of their first K-mount camera, the K1000. They needed an excellent line of lenses to accompany this milestone. And so the Zeiss Distagon 28/2 was also released as the "smc PENTAX 1:2 28mm". This optic utilises 9 elements in 8 groups, including floating elements that maintain excellent performance down to the closest focus distance (30 cm). Like many Zeiss designs, the lens is unusually large and heavy (length 69mm, mass 423g, 52mm front filter). Pentax produced this lens from 1976 to 1981 in two variants that are identical except for their markings. This first line of K-mount lenses are referred to as "K", even though this letter does not appear on the markings or in the official lens designations. But this nomenclature helps distinguish the "K" line from the subsequent "M" series (which are marked "PENTAX-M") and A series (marked "PENTAX-A"). The M line were all re-engineered from the K, following consumer demand, to fit a smaller form factor. This is where Pentax and Zeiss parted ways! The A series are so named because they had an automatic aperture setting... though this is not relevant when they are used on contemporary digital cameras. Many but not all of these A lenses were optically identical to their M predecessors. But the K line are unique and often highly prized by Pentax fans. Note that the official Zeiss specification sheet measures the focal length at 28.8mm for a 74º diagonal angle of view. Most Zeiss lenses have minimal distortion, low flare, insignificant chromatic aberration, good contrast, and accurate colours. This Distagon is no exception. Zeiss Distagon The Carl Zeiss Distagon T* 28mm f/2.8 was released for the Contax-Yashica mount three years after the f/2.0 version (1978) as a more compact (52mm, 280g, 55mm filter) and more affordable option. The optics use 7 elements in 7 groups. Though it can focus closer (25cm) than the f/2 lens, it does not include floating elements. The official specification sheet measures the focal length at 28.5mm for a 75º diagonal angle of view. It is worth mentioning that the name Distagon indicates a retrofocus design, where "the distance between the last lens surface and the film plane is longer than the focal length, allowing unobstructed motion of the reflex mirror" (Zeiss spec sheet). Pentax A The SMC PENTAX-A 28mm f/2.8 was produced from 1984 to 1988. It's more compact than the Zeiss designs at 37mm long, 170g, 49mm filter. The 7 elements in 7 group optic is the same as its predecessor (the second version of SMC Pentax-M 28mm f/2.8) though optical performance is generally thought to be slightly better. Reviewers note its sharpness and dimensional rendering. Close focus is 30cm. For completeness I list the full line-up of manual focus Pentax 28mm lenses: SMC Pentax 28mm F2SMC Pentax 28mm F3.5SMC Pentax-M 28mm F2SMC Pentax-M 28mm F2.8SMC Pentax-M 28mm F3.5SMC Pentax-A 28mm F2SMC Pentax-A 28mm F2.8 Vivitar by KomineFor this comparison I selected two of the best lenses from The Great Vivitar 28mm Bestiary. The Vivitar 28mm 1:2.0 MC Close Focus was manufactured by Komine circa 1983. It is distinctive for the high magnification (1:5) made possible by the 23cm minimum focus distance. It's similar in size to the Distagon f/2.8 at 50mm long and 280g, with 49mm filter thread. I very much enjoyed using this lens on APS-C sensors. Details and photos here. Kino by Kiron The "Kino Precision" Kiron 28mm f/2 MC was released in 1981 for K-mount. It's 51mm long and 270g with 55mm filter and 30cm close focus. It was included in the Bestiary since it's similar to some Vivitar variants and performs well. Details and photos here. I note that my copy appears to have hazy elements. This might be something that's developed in the last decade! Other remarks All the K-mount lenses have the widest aperture to the right and stop down with a clockwise rotation. They include half-stop clicks that are firm and decisive. The Zeiss Distagon, like other lenses for Contax-Yashica mount, have the widest aperture to the left and stop down with a counter-clockwise rotation. It has only full stop clicks that move easier than Pentax lenses. Hence the aperture is quicker to change but does not permit the same fine control over exposure. All these lenses focus from near to far by rotating the barrel counter-clockwise. Test Method At the outset I should declare that I'm not a technician and do not have calibrated test equipment. I compare lenses by shooting them in controlled circumstances, but also by taking them out for real-world encounters. This article is hence less a "test" and more a "comparison". I make no claims for scientific validity. Numerous test shots were made over several weeks, in part because I didn't believe the initial results. I present a useful subset of tests in this Flickr album. Other results not reported here are nonetheless consistent with these. I shot using the excellent Panasonic Lumix DC-S5, a hybrid photography and video camera. The S5 has a 35mm full-frame (35.6 x 23.8mm) CMOS sensor with 24.2 effective megapixels. All photos were taken on a tripod, with shutter timer and IBIS set off. Sensitivity was kept consistent for each set, at either 100 or 640, these being the base ISO values of the sensor in Natural profile. Lenses were set to four aperture settings: f/2 (if available), f/2.8, f/4, and f/8. The raw (RW2) files were batch converted to JPG using Affinity Photo. I did not apply any of my usual development processing. The shared results are from two scenarios. The first subject was my bookshelf at a distance of 60cm. I used 14x magnification on the LCD screen to focus on a region 80% of the way to the right-hand border, this being the closest to the edge of the frame that I could manage. This region corresponds to the "DM" of "BIRDMAN" on the spine of the book. I cropped a 1000 pixel square out of each image, arranging these in a grid for ease of comparison. The first column is at f/2, second column f/2.8, and so on. Here is a comparison of the centre and edge of the frame at f/4.0. Again, these are magnified crops. The second subject is a bunch of yellow roses. Focus is on the centre, with the flower in the top-right also falling into the focal plane. View these in the Flickr album already mentioned. Results The Pentax Distagon acquits itself very well. At f/2 the results are usable, even at the border. The bokeh is smooth and delightful. Vignetting is obvious, as was expected. Improvements in sharpness and contrast are seen when stopping down, resulting in a wonderful f/8 image across the frame. The results from the Pentax-A f/2.8 will not surprise any Pentax fans. From wide open the bookshelf images have improved micro and macro contrast compared with the Pentax Distagon. At f/2.8 the flower image is lovely, with smooth bokeh typical of Pentax. Vignetting is less than the Distagon. The slightly wider field of view is more true to the claimed 28mm focal length. If we turn to the Kino by Kiron it's obvious that border clarity is lacking, though OK at f/8. I had already noticed this while shooting, since it was difficult to nail focus. In the flower image the outer bloom is soft and dreamy. The Kino could be used as a specialty lens for when this effect is desirable. But personally I'd be shooting a longer focal length and wider aperture if subject isolation was my priority. I prefer my wide lenses to be useful for wide shots! The Vivitar by Komine lens proved a winner on a cropped sensor and has a good reputation. But here I found it washed out and hazy, with ridiculous vignetting, hence useless wide open... and not much better until f/8. I was surprised to see that the Zeiss Distagon f/2.8 performed as poorly as the off-brand lenses. Border detail is blurred, especially in high contrast areas. Vignetting is significant. It doesn't appear to handle contrast or colours well. No doubt there is a reason why the Distagon f/2 sells for five times the price. Conclusions Any lens you have will take decent photos. Your gear is not as important as your subject, lighting, knowledge of photography (both technical and aesthetic) and other factors. That said, there is obvious value in using the best tool at your disposal. This test revealed the Pentax-A f/2.8 as the superior option among those lenses tested. This was quite a surprise! But it's been backed up by continued shooting over many months.  Equally surprising was the inferior quality of the Zeiss Distagon f/2.8. And though the Vivitar lens worked well on my old Pentax camera, performance here is poor. This could be because of infinitesimal differences in the mount adapter. Or perhaps this demonstrates the effects of aging (misalignment, haze on lens elements, etc.). I absolutely adore the usability and aesthetics of Zeiss lenses, which is why I also own 50mm, 60mm, and 85mm focal lengths. For me Zeiss has perfect ergonomics while producing clear and accurate images without the colour cast of, say, Leica. Though the ergonomics are different from a true Zeiss, I have very much enjoyed using the Pentax version of the Carl Zeiss Distagon T* 28mm f/2. Though it may not be as sharp as the Pentax-A, images justify its legendary reputation. The following photo demonstrates the incredible rendering which the plain old Pentax-A does not possess. View more examples in this Flickr album. A notable characteristic of the Pentax Distagon is the significant field curvature: corners are focused behind the centre of the frame. With the subject near the image centre, this provides greater isolation of foreground from background, that characteristic "3D pop". (See my article on that phenomenon.) Another lens that demonstrates this effect is the Pentax Limited 43mm... also a favourite of mine. But this quality might make the lens less suitable for edge-to-edge sharpness (e.g. landscapes). Though I haven't made strict tests of this performance, in practice I've not encountered this problem once stopping down to f/8. Of course there are other considerations when choosing a lens, namely price and availability. A Pentax-A f/2.8 can easily be found for €100, making it a bargain for such a compact performer. But the Distagon T* 28mm f/2 is closer to €1500, once you've paid import fees from Japan (where most stock seems to be located). If you get lucky you might find a copy for €1000... but then you are taking a risk that the lens will not perform to par. For my part, I will continue to shoot with both Pentax branded lenses and put aside the Vivitars and other brands. Appendix For reference, these are my original 28mm lens reviews. Looking for the Perfect Normal (31 August 2008) Vivitar 28mm 1:2.8 Auto Wide-Angle (21 September 2008) Vivitar 28mm 1:2.0 Close Focus Wide Angle [K01 Komine] (27 September 2008) Vivitar 28mm 1:2.8 Close Focus Wide Angle [K03 Komine] (1 October 2008) SMC Pentax-A 28mm F/2.8 (5 October 2008)Vivitar 28mm 1:2.8 MC Close Focus Wide Angle [K02 Komine] (12 May 2009) Vivitar Series 1 28mm part one and part two (9 and 10 July 2011)

Which audio production gear? (Robin Edition)
This article follows on my declaration of principles found in "Does your gear matter" located here. As a third-level teacher and trained audio engineer, I am often in a position to recommend audio gear to electronic music composers and producers. In this article I will set out a minimal threshold for professional audio production. Introduction In the post-COVID world hardware costs have risen, due to electronic parts shortages and worldwide distribution problems. For two years it was nigh impossible to buy some of the equipment I will recommend below. As manufacturers retooled to use alternative parts, supplies began to flow, but prices increased by at least 20%. Nonetheless, the barrier to entry is a lot lower now than when I was starting out in audio production in the late nineteen-eighties. In part this is because digital technology has (largely) replaced the need for a physical studio. Though you might still choose to invest in analogue mixers and outboard gear racks, that approach is now a luxury, not a necessity. For most people an entry-level system includes a laptop computer, audio interface, powered monitors (speakers), software recorder/mixer (DAW), and sufficient plugins to enable a reasonable workflow. The goal is to reach a minimal standard of excellence. Though this article presents my personal analysis, it conforms to a standard of practice in electronic composition and production. Indeed, I decided to update this article after a conversation with composer Lionel Kasparian, who recently presented a seminar at DMARC, the Digital Media Arts Research Centre at the University of Limerick. In that seminar he answered questions relating to similar concerns over gear. I realised we had a very similar approach, even down to the exact interface. Hence this article! Laptop A previous article recommended an amazing laptop that forgoes Apple's over-priced and over-restrictive systems for a refurbished Lenovo. Buying a model a couple generations old loses nothing in performance but saves a significant amount on price. Please note that audio production is far less demanding than video work. So unless you have special needs, for example large orchestral libraries, a system such as this is entirely sufficient.  Purchase a Lenovo ThinkPad X390 with 16GB RAM for only €300 (including one year warranty). Replace the M.2 SSD with a Samsung 970 EVO Plus at 1 TB capacity for €100. I sometimes get push-back from people claiming that a laptop like this can't possibly be good enough. So let me emphasise. Reviewers focus on high-end expensive gear, leading people to believe that the latest greatest tools are necessary for you to get your work done. Nope. As mentioned, you need to reach a minimal standard of excellence across your tools. Anything else is gravy. It's worth mentioning that a desktop computer is more upgradable, more flexible, and more powerful than a laptop. But I recognise that very few people are interested in a larger computer system, so I leave that topic for other articles. Audio interface Your sound card is your most important piece of kit. And there is only one brand to buy, unless you have substantially more money. Forget Tascam, Focusrite, Avid, SL, and all other brands. Buy only RME. Why? RME are the only company who write their entire firmware stack, for ultimate driver stability. RME are the only company to support their gear going back decades with contemporary driver updates. RME are the only firm likely to repair a 20-year-old device for free. (They did for me.)  RME are the only company to provide the wonderful TotalMix software that does everything your DAW can't. Once you learn matrix mixing, there's no going back. I can easily tailor four stereo pairs of outputs with signals derived from any combination of inputs. That's like having a mixer with 8 aux sends. Except better. The RME Fireface UCX II costs €1380 for 8 analogue ins and outs plus much digital connectivity. You might look at that price and say "What! Robin, are you crazy? I can buy an audio interface for a fraction of the price!" Yes, you can. And if you are lucky, it just might work without glitches. But now re-read the previous paragraphs. The RME is superior in sound quality and in every other respect. The time you save in diagnosing frustrating audio problems will save your sanity. This unit can work as a standalone recorder to a USB drive. Essentially you are getting three devices in one: an audio interface, a field recorder, and a multichannel matrix mixer. If you don't mind losing the field recorder functions, you might instead locate the Fireface UC second-hand for under a grand. (RME also sell the Babyface Pro FS at €820 but I find that form factor annoying.) Active monitors For active monitors consider a pair of Genelec 8020D for around €900. These may not be the ultimate speakers... for that add a couple more zeroes to the price. But Genelecs have the advantage of being something of a standard (at least in academic circles) so no matter where you go in Europe, you will find Genelecs in the studio. Your production will translate exceedingly well between their entire range. This is a benefit that doesn't apply to other manufacturers.  If you want 10 Hz more extension on the lows and have an additional €300, consider the Genelec 8030C. Either way you will need to budget for cables and stands, about €300. The problem with speakers is that you need a good listening room. This is less an issue for near-field monitors, which are designed to be close to your head. With more direct sound getting to your ears, reflections and room modes are less relevant. Nonetheless, the cost to treat a room can easily get into four digits. When you are getting started, it's more economical to instead buy good headphones... which you will need in any case. Headphones  When I trained as an audio engineer, the very idea of mixing on headphones was sacrilege. Closed back cans were useful for tracking, but no-one would ever think to mix without speakers. But times have changed and most people now listen binaurally, on headphones. So why not mix that way? Just make sure you are buying full-range open-back headphones to get the smoothest response. Let me be a heretic here, and say that it might even be possible to skip the speakers so long as you have good headphones. This is true if you have occasional access to someone else's speakers, so that you can check your mixes in open air. I have always trusted AKG, ever since they were exclusively known to engineers. Now that their line is cluttered with consumer models, it can be difficult to know which are the best value. I recommend the AKG K-712 Pro which are a bargain at €270, or a bit less for a B-stock pair at Thomann. The AKG K-612 Pro has a similar frequency profile for only €150, indeed perhaps it's even smoother in the mids, though weaker in the bass. Unfortunately the cables aren't detachable, which is a bummer.  Also consider the Sennheiser HD 600 at €340. They have a detailed, open sound but the impedance is much higher, so you will need a good amp to drive them. This is not a problem with an RME interface, by the way, since the headphone output has tons of power. But you won't get the best out of these headphones if you are using a mobile device, including a laptop headphone socket.  As an aside, if you need closed headphones for the studio floor, you can't go wrong with the AKG K-271 Mk II at only €115 for a design with replaceable cord and unique auto-off switch. So when you remove the cans from your head, the signal cuts off, avoiding feedback from any open mics.  Software Most music producers need a DAW... and there are so many of them that it's impossible to say which application will suit your workflow. But you can't really go wrong with Reaper, which provides substantial bang for your buck, considering that you can use it for free. Once you go commercial, send them $225. Once. No subscription or other hassle. If there's one application that I recommend for the sound designer, it's Reaktor from Native Instruments. This development environment comes packed with thousands of synths, sequencers, effects, and other tools. You might prefer Max for generative work, but it's a lot more expensive and time-consuming to use. Reaktor gives you ready-to-use instruments, so you only need to hack if you want to. It goes on sale for €100 a few times a year. You don't need to spend any money on plugins. There are so many good free tools, starting with those that come packaged with your DAW. My recent article recommends favourites. Conclusion To start in electronic music production spend €1700 for a second-hand RME interface, laptop, and headphones. Later add Reaper and Reaktor for €300. If you need to, add another €1200 for speakers and accessories. You could work for a decade with little more. Spend the rest of your time learning your craft.  If you wish to record acoustic instruments then things get more involved, since you will need a quiet environment and a decent microphone or three. My experience is dated on such matters, so I will leave this topic for someone else!

The best free audio plugins (Robin Edition)
It's been a while since I wrote an article in this series. Perhaps because I don't obsess over tools and am happy with what I have. Or perhaps it's more accurate to say that I don't always obsess over tools... but when I do, I like to share with you!Recently I've been asked what plugins I would recommend, assuming that you have no cash on hand. The problem is not finding plugins, as there are so many. The problem is finding tools worth using.  Unlike other areas of music production, you don't need to spend any money on plugins. Seriously. Likely your DAW already comes with the "basics"... which translates to tens of thousands of dollars of outboard equipment, the likes of which we could only dream of back in the 1980s. So, start with those. Learn them well.  When you wish to extend your palette, these are the best free tools I've uncovered. I'll divide these into two categories: instruments and effects. Instruments For sample-based instruments grab Decent Sampler and then cruise to Pianobook for instruments to load into this player. Spitfire Audio Labs quite generously provides many free sample-based instruments, alongside their professional libraries. Native Instruments entice you into their product line with Komplete Start, which includes Reaktor Player and Kontakt Player, loaded with six synths, several sample-based instruments, and so on.  Personally I don't rate the quality of most of these, but it's good to have Kontakt on hand. Web searches will reveal many individual sample packs for Kontakt, though the best of these might require the paid version. Look out for that. If you prefer to avoid the big companies, the following three synths will do just about anything you need: Dexed is a DX7 emulation that reads all archival patches from that famous Yamaha FM synthesiser.  Surge XT is a subtractive synth with wavetables, FM, etc. that supports microtuning, MPE, etc. Emulate analog goodness! SunVox is a modular synth with a pattern-based sequencer (tracker). I must mention that the full version of Reaktor goes on sale for 100 clams twice a year. This includes several thousand effects, synths, sequencers, and so on... plus the ability to make and hack your own. Yes, it's not free, but the per-instrument cost is only pennies. Effects Check out Tokyo Dawn for: TDR Molotok, a zero-latency compressor with side-chain. TDR Kotelnikov, a mastering dynamics processor with sidechain filter. TDR Nova: parallel equalizer with dynamics processing. TDR VOS SlickEQ: 4 EQ models, 5 output stages, and saturation. Valhalla offer several worthy plugins for $50 each. I couldn't do without VintageVerb and Room. But they also generously offer the following free of charge: Space Modulator: flange algorithms  Supermassive, a huge reverb/delay  Freq Echo: frequency-shifted echo Here are other effects that top my list: Wings Fire multiband distortion Tritik Krush: bitcrusher, clipper, multi-mode filter Deelay: multifunction delay Driftmaker: disintegration delay GSi VariSpeed: emulation of a WEM Copicat IC-400 belt drive delay FerricTDS mkII tape dynamics simulator Couture Free Edition: transient shaper And finally, two essential tools for getting your mix right: Youlean Loudness Meter Voxengo SPAN, a spectrum analyzer Further ReadingRecent articles in the same series: Three Amazing Audio Plugins: Sketchcassette, Shapeshifter, DigitalisPiano Plugins: An Overview of Inexpensive Options Part One and Part Two

Cheap lens equals excellent lens?
St. Mary's Church interior @ F4 Though sometimes I recommend lenses that might cost a few hundred clams, today I am evaluating a SMC Pentax-M 50mm F/1.7 that was €49 plus a tenner for shipping. If you are lucky enough to be in a populous country with boot sales or pawn shops, you might well find this model cheaper. This lens was last manufactured 40 years ago, so I am somewhat late with this review! The 50mm focal length is the most common for full-frame cameras. Back in film days, before the advent of auto-focus and the popularity of zoom lenses, almost every camera body came with a "nifty fifty" attached. Among manufacturers, Asahi were in high regard. Between 1964 and 1974 they produced Takumar lenses for the M42 screw mount in F1.4 and F1.8 apertures. There were numerous variants with the following prefixes: Super, Super-Multi-Coated, Multi-Coated, S-M-C, and SMC.  In 1975 Asahi dropped the Takumar name in favour of Pentax and moved to the bayonet K-mount. Three chronological series were released (K, M, and A) followed by the auto-focus lines. These were variously produced in F1.2 and F1.4 apertures, with an F4 macro as well. There was also the similar 55mm focal length, which saw almost as many models. Sometimes the optical formulas continued from one range to another, but just as often changes were made. This means that there are likely hundreds of thousands of such lenses in existence, all in various stages of wear-and-tear. An old lens might have a slow aperture (due to oil on the blades or evaporation of lubrication), serious glass scratches or chips, an abundance of internal dust, fungal infection, locked aperture pin, balsam separation between elements, haze due to sublimation of materials, or damaged filter ring... just to name the most common ailments. The biggest challenge is not finding a 50mm lens, it's finding a good copy. Only Japanese sellers are fastidious and honest in reporting condition, but the shipping, duty, and tax fees add another 50% to the purchase price (at least here in Ireland). St. Mary's Church exterior @ F8 The Pentax 50mm lenses were more similar than different. They all have 45cm close focus distance and a 6 element in 5 group design. The barrel length ranges from 31 to 42mm and weight from 185 to 265 grams. The filter thread is either 49mm or 52mm. The SMC Pentax-M 50mm F1.7 is tiny, characterised by the smallest of the numbers in each case. Due to the lens being so tiny, the aperture and focus rings are close together, but you are unlikely to mistake them with practice. Mounted on my Lumix S5 the bayonet adapter provides a useful stand-off so handling is not a problem. The build is all metal and glass, complete with the distinctive cloisonne (shippoyaki) nub.  This lens has an aperture with solid half-click from F1.7 to F22, alongside a convenient depth scale. The focus ring is nicely damped and turns from infinity at the left to the position marked 0.45m in just about 200 degrees. For photography this is a perfect throw. I had no difficulty attaining precise focus. All of this is entirely typical for Pentax lenses of the period. I do prefer the Contax Zeiss single aperture clicks, which are smoother and easier to make blind. For my usage I never never need half stop apertures.  Rin-Rin at F2 The shots in this article are unprocessed except for my usual development in Affinity Photo. The results are clear and sharp, with no obvious aberrations, distortion, or even vignetting. Granted, I have cropped these slightly, so you'll have to believe me on the last point.  Rin-Rin was shot at the closest distance possible. There's sharpness without forsaking a natural look. I'd guess this is a good portrait lens, because you rarely want tack sharp skin. It's simply not flattering. I love the smooth transition to the background. And though I wouldn't characterise this lens as having that 3D pop I recently wrote about, I don't miss it either.  The shots of St. Mary's church render the colours exactly as I saw them. The altar is filled with creamy light, due to the interior colour scheme, while the tower is lit sharply against the blue sky.  top to bottom: F1.7, F2.8, F4  I also did some informal test shots, using F1.7, F2.8, and F4 as points of comparison. I have no overwhelming desire to use a lens wide open if stopping down a little gets better performance, as it usually (but not always) does. The number plate above is typical of lens performance. Each reduction in aperture cleans up the image significantly, with greatest detail and sharpness at F4. Despite this evidence I kept shooting at F2 and was rewarded when the subject matter was chosen correctly. The colourful items that just happened to be on my kitchen table look pretty fabulous. In fact, I'd say that here the subject is starting to pop. This photo also provides an opportunity to critique the bokeh, which is only slightly less than creamy smooth.  kitchen colours @ F2 In conclusion, this lens is an amazing bargain. It wants for nothing, in my opinion, except a Zeiss build. (Oh well.) You could spend a lot more and get some trendy East German or Russian swirling bokeh monster, as is the current trend. But this superior glass is more suited to a variety of subjects and shooting scenarios.  For more opinions you can peruse the 17 pages (!) of reviews on Pentax Forums.

Does your gear matter?
Does your gear matter? Simple answer: yes. Those populists who say otherwise are perhaps simply currying favour. Or, to be generous, perhaps they are attempting to counteract the overwhelming commercialisation of the internet, where everywhere you turn someone is proclaiming the newest trinket to be the GOAT (Greatest Of All Time). But both extremes are wrong. The newest tool won't make your practice better. But it's also true that ignoring the quality of your gear is foolish. This article will assert the review principles that I abide by, so as to place my articles here in the correct context. It should be plain to anyone who has tried to learn music that a poor instrument is detrimental. You can't finger nimbly if the string tension or height above the fretboard is wrong. A split reed doesn't sound right. You can't get good tone out of a cheap string. Using a poor instrument can instill bad habits or frustrate the learner to the point that they lose enthusiasm. Considering that I am trained as an audio engineer and teach on a media course, I often get asked my advice about gear for audio, photography, and video. Sometimes the reply does not suit the questioner, since there exists a threshold of expenditure that one must commit to. Spend any less and your equipment will hamper your tasks. Spend any more and you get only incremental benefits. Somewhere in between is a sweet spot, but that is rarely found at the cheapest end of the spectrum. Sometimes the answer is disappointing for the opposite reason. If someone invests a substantial sum in an item, they have a vested interest in believing it is a wonderful tool. I have been a critical thinker since I bought my first synth at age 17. I immediately saw the value in a different keyboard, and traded my Korg for a Moog. I then stuck with that device as the optimal tool for the money. Had I been wedded to my first choice I would have done myself no favours. In some disciplines there are bargains to be had. One of the goals of this blog is to highlight tools whose value is out of proportion to their cost. That's why I've been actively testing lenses lately. My first step in this process is to read voraciously to determine recommended options. Then I can obtain a few of the most likely solutions, compare these for myself, and eventually narrow a large field to a small toolkit. I share this process not to feed my own ego, but to make life easier for those that follow my footsteps. I hope that you can trust my reviews and opinions, which come from a questing belief in finding optimal solutions. My general principle, after years as a starving artist, is to be frugal, to limit consumption, and to enjoy what I do own to the fullest. If occasionally I recommend a more expensive option, it is because that tool provides substantial benefits that cannot be found elsewhere. Please bear these principles in mind as you read my audio, photography, and computer articles. These are extensions of my practice as a researcher and teacher. I have no interest in encouraging over-consumption, as that is antithetical to my lived ethos.

That elusive "3D pop" defined
"Chris" with the Pentax-FA 43mm Limited Photographers have argued for decades about a certain appealing quality of an image called "3D pop". Some claim that it doesn't exist. Others concede that it does exist, but deny that lens design has anything to do with the effect. Those that promote 3D pop sometimes resort to hyperbolic claims about the characteristics of certain vintage lenses that (they claim) cannot be found in contemporary glass. The subject is so heated that a few years back it spawned a parody article which, in my opinion, did more harm than good. Here's my take: 3D pop exists and can be well described. Certain lens designs encourage the production of this effect. While it's not necessarily true to say that older lenses are required for 3D pop, specific vintage lenses are desirable, for reasons that will be explored below. 3D pop and its requirements We can define 3D pop as that characteristic of an image where the subject has a certain dimensionality, a sculptured profile, that allows it to be clearly distinguished from its environment. Given that a photograph is only a two-dimensional representation of a three-dimensional scene, we rely on visual cues to indicate depth. We can make a more general claim that interpreting images is an experiential process, one that must be learned and is culturally determined. Nonetheless, our understanding that visual interpretation is contextual doesn't mean that 3D pop is illusory or can't be defined. Let's examine the components that go into producing this effect by first explaining factors exterior to the lens itself: light, subject placement, and perspective. Then we can examine lens design. Almost all good photography requires suitable light. This is why photographers and film-makers alike have long favoured the "golden hour", that special period in the early morning or evening. During this interval sunlight travels through more of the Earth's atmosphere to reach us than if it was, say, directly overhead. This provides the light with a warm tint, which can be favourable to skin tones. The light also becomes more diffuse, reducing harsh shadows. There are other cases where light might be especially appealing and most of these have to do with directionality. Consider the classic three-point lighting used in portraiture. Second, it is helpful to have a certain longitudinal subject to environment distance, which is to say space around the subject that acts to physically separate it from the background. Consider the portrait above. The background is blurred, though one can still see just enough to get context. Quite often images with large areas of bokeh are put forward as demonstrating 3D pop, but this is not a sufficient condition. The following photograph demonstrates that it's not necessary to blur the background into obscurity. Even the small distance between the stone and the rock surface behind is enough for a clear and distinct delineation between the two. It also helps that the textures and colours of the objects differ substantially.  "Shadows cast" with the Pentax-FA 43mm Limited Third, we must choose our perspective, the position of the camera relative to the subject, so as optimise the angle of light and distances involved. In the photo above the light is at 45 degrees to the camera axis, which aids in distinguishing the stone from the surface. Even when all external factors align, some photos have the elusive "pop" and others do not. The remainder of the effect can be attributed to the lens itself. Some lenses I've used never pop. Other lenses make it rather more likely. Diving into the depths 3D pop relies on depth of field (DOF) which is worth explaining in some detail. DOF refers to that distance before and behind a focused subject in which the photograph appears sharp. But note that the plane of focus actually has no physical depth. Everything not in the focal plane is out of focus... but to a greater or lesser degree. Hence DOF is perceptual. It depends on the "circle of confusion", defined as the smallest region that can be clearly discerned by the average person under normal conditions. Since this is subjective, different standards exist for specifying the size of the circle of confusion. Furthermore, not all conditions are "normal". We can expect DOF perception to vary with factors like lighting, as discussed above. And since we are not all "average", some people will see 3D pop easier than others. DOF is further determined by two objective measurements: the magnification factor of the image on the sensor and the lens aperture. For a given circle of confusion, magnification itself depends on lens focal length, subject distance, and the size of the sensor that is registering the image. Shooting with a longer focal length can help a subject pop, since it compresses the subject-background distance in the resulting image. But there are plenty of counter-examples, such as the 28mm lens described below. Modulation Transfer FunctionAn MTF chart displays lens information we can use to evaluate optical performance. Typically such a chart will have three curves: 10 lp/mm for large structures, called macro-contrast, global contrast, or simply contrast 20 lp/mm for medium structures, called micro-contrast, local contrast, or resolution 40 lp/mm for small structures, called acutance The unit is line pairs per millimeter. We get these values by measuring contrast transitions between edges of parallel lines. Sensors have resolution (AKA spatial frequency) of 100 lp/mm, more than sufficient for anything our eye can discern. The lens we use is the limiting factor.Not every manufacturer will use the same line pair curves. The standard 40 lp/mm was chosen because it is sufficient for an 8x10 inch print enlarged eight times to be perceived as sharp. This bring sup yet another important consideration: the type of display, size of display, and viewing distance all have a significant impact on 3D pop. An image viewed on a phone screen might not pop, but when printed it might.Check out Koren and Mansurov in the references for a more detailed explanation of MTF and related subjects. "sheep" with the Pentax-FA 77mm Limited Sharpness and all that So what is sharpness? Though often used colloquially without clear meaning, sharpness is defined as a combination of resolution and acutance. A necessary (but not sufficient) condition for 3D pop is that the focal plane be rendered with both high contrast and high sharpness. This is known as "bite". A lens with bite has other beneficial properties. It's easier to achieve manual focus since the subject snaps crisply into focus. Autofocus mechanisms similarly benefit, especially those based on contrast detection. In his article "Micro Contrast and the ZEISS ‘Pop’" Lloyd Chambers defined 3D pop almost exclusively in terms of such attributes. The aperture used is not as important as many think. We don't need to use a lens wide open because 3D pop does not require blurring the background into oblivion (as we've already seen). A tack sharp lens can still produce 3D pop when stopped down. This example from the Chambers article was taken at F5.6. What is perhaps more important is that the aperture is chosen to provide a DOF that ends at that border between subject and background. The subject will bite, but the background won't. An intriguing observation can be made here. You can view photographs taken with two different lenses (at same aperture and focal length) and they will appear to have different depths of field. Greater bite can increase the perceived DOF.  Sharpness and contrast are negatively impacted by any number of optical defects, including spherical and chromatic aberrations. Hence a lens optimised for 3D pop needs excellent correction in all areas. A lens hood is mandated to avoid flare. Internal reflections can be a further problem, especially when adapted vintage lenses onto mirrorless cameras. Given the above design challenges, it's not surprising that a lens suitable for producing 3D pop might well be expensive. Which is also why many fledgling photographers might not be able to demonstrate this effect for themselves, with their kit lenses. This leads to scepticism that 3D pop even exists. The need to spend money and be specific about lens choice leads deniers of pop to accuse believers of simply asserting their prestige. We can now understand why this might be so. "Dave on his birthday" with the Pentax-FA 77mm Limited Pentax Limited designs The next optical factor is rather more obscure. It's something that I learned from Jun Hirakawa of the Asahi Optical Industries Research and Development Centre. Hirakawa designed several amazing lenses for Pentax, including the SMC Pentax-FA 1:1.8 43mm Limited and 77mm Limited models that I've used to illustrate this article. Here's a translation of page 80 of a technical report he wrote in 2000: The Limited lenses have achieved a level of aberration correction unattainable by earlier concepts. That is to say, without giving priority to resolving power, MTF values and other numerical evaluations, they attain a level of correction in actual photo capture that remains in your mind. This is because currently the subject plane is the target of this numerical evaluation, and thought not to be a suitable evaluation of the depiction of solid objects. Certainly, we think evaluation of object depiction by the numerical value method should be established urgently, but for the time being, that comes after the design. Simply stated, MTF gives us information about the focal plane only, but since objects are three-dimensional there is more to rendering than this. Standard lens design of the era (1990s) had a goal of a flat subject plane, so that MTF curves looked better to users... and reviewers. I would wager that this is even more true of contemporary designs.  As a technique to correct aberration, the meridional subject plane is fully corrected and the sagittal subject plane is left slightly under corrected which makes the mean subject plane virtually flat. However, with this correction method sagittal and meridional subject planes open up at middle angles leaving an astigmatic difference. Thus the subject plane is flat making it excellent in numerical evaluation, and you can take a picture with uniform field, but in reality it will lack spice. In the pursuit of better MTF scores, designers allowed astigmatism to remain in the optics. But what if instead we made the opposite compromise: sacrifice the flat plane of focus in order to fully correct astigmatism? This is exactly what Hirakawa did. With the limited lenses, even though small amounts of field curvature were left, meridional and sagittal picture fields were fully corrected. In this case, evaluation of the plane isn't so great, but when capturing solid objects astigmatic difference is completely gone, allowing the point of focus to be sprucely depicted. The 43mm and 77mm Limited lenses are distinctive in being specifically designed to allow field curvature. So long as the subject is in the centre of the frame, it will bite. The curvature will only help to enhance the distinction between subject and environment by pulling (or pushing) the latter out of focus. This allows a "sharp but gentle" depiction of the overall scene. Furthermore, CA was corrected in some new manner, left unexplained. Just as well, because these lenses do unfortunately demonstrate colour fringing. The Limited lenses weren't merely corrected for axial chromatic aberration and aberration of magnification, correction tor various wavelength characteristics were carried out. Focus point for each color and out of focus boundaries were aligned, allowing a gentle transition from the solid subject to the out of focus portion. The above aberration corrections which are a bit different from previous ones, were carried out with the Limited lenses. The priority given to rendering real-world dimensional objects and not the idealised focus plane results in "a gentle transition from the solid subject to the out of focus portion" of the image. If the lens also bites, we get an image like the following. comfy chair [SMC Pentax 1:2/28] The case of Hollywood Pentax was not the only company to design lenses in this way. In fact 3D pop is most often attributed to Zeiss lenses, sometimes as though it is an exclusive property of that brand. Consider the Carl Zeiss Distagon T* 28/2.0, produced for the Contax/Yashica mount. This lens has achieved a legendary reputation for its rendering, as much prized for cinematography as photography. Designed by Erhard Glatzel, the Distagon marks the only collaboration between Pentax and Zeiss. In 1976 Pentax were moving their system from M42 screw mount to a brand new bayonet mount. For the launch of their first K-mount camera, the K1000, Pentax wished a distinctive and superior line of lenses. The resulting K-series are still highly regarded today. The Pentax counterpart to the Distagon was the SMC Pentax 1:2/28, which stayed in production for five years. But photographers soon desired more compact lens designs. Pentax provided these with their M range, while Zeiss persisted with lenses that were often significantly larger. Reviewer Jannik Peters provides a relevant description: The Distagon shows a significant amount of field curvature. The plane of focus is comparable to a sphere around the camera. The extreme corners are focused significantly behind the center which will result in a greater subject isolation towards the edges (in comparison to a lens with a very flat field of view). The impression of depth of field is more shallow than the f/2 value may suggest. This property of the lens defines it’s character and is great for close-up photography with shallow depth of field since it conveys a three dimensional impression. Indeed, this lens readily produces that coveted 3D pop, even though it renders a wide angle of view. This effect is perhaps easier to achieve at near distances, where the floating element provides for excellent close focus performance. In the interior shot above, the comfy chair pops out from the background in a most pleasing manner.  Limerick roundabout [SMC Pentax 1:2/28] But even more interesting is how the dimensionality remains present for distant objects... even when the lens is stopped down. One might not wish to call this "pop" but there is something special about the dimensionality of the Limerick roundabout photo above, though shot at F8.  Conclusions 3D pop is a desirable characteristic of an image where the subject is rendered with a pleasing dimensionality that allows it to be clearly distinguished from its environment. This effect is created by a combination of ideal light, appropriate subject to background distance, and perspective. Furthermore, it requires a lens that is free from optical defects, with high measurements for sharpness and contrast, at least in the part of the frame where the subject is located. Furthermore, a lens that does not perfectly correct field curvature can enhance 3D pop. Background blur and separation are not the same as 3D pop, though they might enhance the effect. A wide open aperture is not essential and might even be counter-productive. Instead, choose the aperture that most clearly isolates the subject. And what about contemporary lenses? Have they somehow forsaken this look? I would largely reply "yes" but not because they have more lens elements, as sometimes proposed. New materials and computer-aided design techniques allow the manufacture of complex optics with a precision simply not possible decades ago. Hence the best modern lenses are highly corrected and also have a flat field of view. This produces a "better" lens on paper, and likely also in operation, but the results might not pop like certain vintage lenses.  That's fine, because though desirable in some photos, we don't always want 3D pop. Sometimes the goal is a homogenous image from corner to corner. This is why photographers might own several lenses that overlap in focal length, each useful for a different purpose. My Pentax-A 28mm F2.8 is better for landscapes than the Distagon, and is much smaller as a bonus!I wrote this article because I tired of reading simple assertions. As a practice, photography is complex, nuanced, and subjective. Every photo is a combination of myriad factors including decisions made by optical designers years ago. If nothing else, I trust this article has demonstrated that truth. bee on yellow flower [Pentax-FA 77mm with macro adapter] References Chambers, Lloyd. 2017. "Micro contrast and the ZEISS ‘pop’," Lenspire [website], 29 August 2017. available Hirakawa, Jun. 2000. "Lens technical report. SMC Pentax FA77mm, F1.8 Limited and FA43mm, F1.9 Limited," Photographic Industries 58.1, 78-81. abstract scans Koren, Norman. 2013. "Introduction to resolution and MTF curves," Norman Koren Photography [website]. available Mansurov, Nasim. 2020. "How to read MTF charts," Photography Life [website], 12 February 2020. available Peters, Jannik. 2016. "Review: Contax Zeiss Distagon 2.0/28 T* AEG (C/Y)," Phillip Reeve [website], 30 April 2016. available

Comparing fast vintage lenses (50mm F1.2)
I've been slowly going through my older lenses and seeing what works best with my Lumix S5. Historically, most of my photography has been on Pentax APS-C and Micro-Four-Thirds formats. A vintage lens made during the film era is more suitable for a full-frame sensor in terms of coverage, but any issues will show up more plainly.  With that in mind, I decided to perform a quick comparison of three lenses I have on hand: Cosina 55mm 1:1.2 MC, SMC Pentax 50mm F1.2, and Zeiss Planar T* 50mm f/1.4. The Cosina 55mm 1:1.2 MC for K-mount is 44mm long and 325g. It takes 58mm filters. The aperture ring has stops at F1.2 and F2, then single stops to F16. The open aperture F1.2 is on the right side of the ring. There are 9 aperture blades. Unlike the full metal build of the other brands, the Cosina has a rubber focus ring. This detracts from the impression the lens gives, but might be useful if you shoot in cold environments. The history of this lens is intriguingly complicated. Tomioka originally designed these lenses for M42 screw mount, and branded them as Tominon, Cosinon, Revuenon, Yashinon, and Chinon. Only a few were sold between 1970 and 1974, so they are now highly collectable, selling for €1300. Cosina then bought the designs but changed the optical formula, marketing new variants, the most common of which is the Porst Color Reflex MC AUTO 55mm 1:1.2. You can buy one for only €225, the cheapest option for a very fast 50. The third generation were Cosina's own optics, different again from the previous. These were marketed for K-mount as Revuenon (again!), Rikenon, and Vivitar Series I. Cosina has a long heritage of camera and lens manufacturing and so should not be considered inferior to Tomioka. In fact they have very collectable lenses of their own under the Voigtländer brand. The lens I have here fetches €500. Soon we will see if it is worth that price.  Though the names of the first and third generations are sometimes identical, it is easy to tell them apart. The first generation have the name "Tomioka" emblazoned on the lens rim, have a 9 blade aperture and a 58mm filter ring. The third generation of Cosinas have 8 blades and a 55mm filter. The SMC Pentax 50mm F1.2 was in production for the K-mount from 1975 to 1984. It's one of many highly regarded 50mm lenses that Pentax released. In 1984 it was replaced by the SMC Pentax-A 50mm F1.2 which is identical except for an automatic aperture coupling. This remained in production until 2004, when Pentax finally brought out lenses with auto-focus. The Pentax lens is slightly longer (49mm) and heavier (at 345g) than the other lenses in this comparison. It has a 52mm filter.   The aperture ring has an unmarked stop between F1.2 and F2 that is actually F1.7. From there it has stops and half-stops to F22. The open aperture F1.2 is on the right. There are 8 blades. Current price is €350. You can expect to pay another €100 for the A variant, since the auto aperture feature adds value for Pentax DSLR owners. The Zeiss Planar T* 50mm F1.4 was made for the Contax-Yashica mount starting in 1975. Zeiss is very exacting with their specifications, and makes clear that this is actually a 52.3mm lens with an angular field of view of 47°.  The lens is compact at 41mm length, mass 290g, filter ring 55mm. The aperture ring has full stops only from F1.4 to F16. The open aperture F1.4 is on the left (opposite to the two K-mount lenses). The aperture ring turns with less resistance than the others, but has friction enough to prevent accidental changes.  You can purchase a mint copy for around €250 for the original AE version and €350 for the subsequent MM version. This was not known to be improved other than the addition of the automatic aperture coupling (irrelevant for digital use), so the main difference is the lack of ninja star bokeh at wide apertures. The extra cost may seem unjustified, but the MM lenses have a reputation for being "better" across the line, even though only some models were improved. Zeiss made a similar 50mm F1.7 lens starting in 1980 that has similar optical performance. But the build incorporates plastic, normally anathema to this company. The bokeh is more nervous and the lens doesn't focus as close. The price of around €140 makes this option more appealing! All three lenses extend slightly at close focus distances. The filter rings do not rotate. The Zeiss and Pentax focus down to 45cm while the Cosina manages only 60mm. The optical formula in each case is 7 elements in 6 groups. In fact, the diagrams for the Zeiss and Pentax look very similar. Comparison To test these lenses in non-scientific fashion I took tripod shots of my bookshelf at a distance of about 120cm. For the first set I focused on the centre of the frame, using various apertures. I batch converted the original Raw files using Affinity Photo 2 with no processing applied. Real-world photos will look better, because the detail, contrast, and other aspects would be tweaked.  I took notes from the full-sized images but haven't shared all of those files. When you see the full frame it's clear that the Zeiss and Pentax demonstrate significant vignetting, as we would only expect, which clears up already by F2.8. The Cosina is already quite clear at F2, which is surprising! Though vignetting can quite easily be corrected in software, the darker image skews exposures.  To create the following grid I took a 500 pixel square crop from the centre of each photograph. Click through to see the full-sized image on Flickr.  Looking first at the wide open image, the Pentax has significant halation and purple fringing. I am surprised to see that the Cosina has fewer of these artefacts. The Zeiss has the best image with already sufficiently sharp text and very little colouration.  As the Zeiss is stopped down it improves only slowly at first. F2.8 is tidier but the best image is reserved for F8. The Pentax improves significantly at F2, sharper than the Zeiss (which I now suspect may not have been focused perfectly). All the purple fog has gone. At F2.8 the text is crisp. At all stopped down apertures it beats the Zeiss marginally but obviously. I am not surprised, since Pentax has always been one of the very finest lens manufacturers. The Cosina is also nice and tidy at F2 and to my eyes produces the best image in terms of sharpness, contrast, and detail throughout the aperture range.  For the next series (image above) I focused on the extreme right of the frame, or at least as close as I could get the 10x magnification to work. Here the significant difference in angle of view is obvious. In fact, it appears to me as though the Cosina might be closer to a 60mm focal length than the stated 55mm.  The Zeiss becomes useful at F2.8 and is very nice at F8. The Pentax is very close but lags behind. The Cosina again suddenly snaps into clarity with F2.8 and then improves slightly from there. I was surprised that this behaviour was so consistent across the lenses.  This test is somewhat artificial, since one rarely focuses on the edge of the frame. It's useful for seeing the absolute quality of the glass, but doesn't reflect field curvature. So I had a look at the frame edge on the first set of photos, where I had focused on the centre. I only checked out the F8 photos, since I would always be stopping down if I desired an image to be sharp corner to corner. The Zeiss seemed ever so slightly more accurate than the Pentax. But the Cosina seemed to have a further advantage of acuity and contrast.  Finally I turned to a shot that would test depth of field. I focused on the tip of the petal that is both lowest in the image and closest to the camera. The focal distance is about 60cm. (In retrospect I should have lit the subject more clearly.) In order to show more context, each crop is now 1000 pixels square.  All the observations from the bookshelf still hold. But now we can see how the bokeh compares. The Zeiss is the most nervous, which agrees with my usage. The Pentax is smoother and more pleasant. Even at F8 I prefer how it renders the greenery that is behind the plane of focus. In truth, this is a torture test for any lens! The Cosina wide open has more definition to the bokeh, with outlines around the circles. It's a matter of taste as to whether that is desirable. Stopped down, the background is smoother than the others, but this is largely (if not entirely) the product of the longer focal length.  Conclusions What did I want out of this comparison? Simple: I wanted the Zeiss Planar to win! I love the ease-of-use of this lens. The aperture moves smoothly, the markings are elegant, the way the two rings (focus and aperture) match texture is refined. And it's the smallest of the lot. As industrial design the Contax Zeiss range is matched only by certain Leicas.  But the photos I've taken, while perfectly good, lack the magic of my best optics. Maybe I need to give it more time, but today's test indicates that I already have better options to hand. I have great respect for the range of lenses Pentax initially made for their K1000, the first camera to showcase the K-mount after they moved from the M42 screw mount. I have long assumed that the most expensive of the so-called Pentax-K 50mm lenses, the F1.2, would be the best possible 50mm. My Cosina has been sitting in a drawer but I need to rethink this state of affairs! Because this lens has emerged as the sharpest of the three, with a better image wide open and a better image at the edges when stopped down. The bokeh may not be as ultimately smooth as the Pentax, but it is perfectly lovely. And I personally prefer the slightly longer reach.  Since I have no photos to share from the Cosina, I will instead demonstrate just how special the wide open Pentax can be. If you are a bokeh fanatic, take note!

The very excellent Vivitar 135mm f/2.8 Auto Telephoto Close Focusing lens
Some years ago I reviewed this lens by adapting it to the Micro Four Thirds system. I was having fun today, so thought I'd remind my readers of this amazing lens, while sharing photos taken on a full-frame system. Before proceeding, it's important that you don't confuse the "Vivitar 135mm f/2.8 Auto Telephoto Close Focusing" lens under discussion with the "Vivitar Auto Telephoto 135mm 1:2.8". There are two obvious differences: the inclusion of "Close Focusing" in the name and the filter size: 62mm versus 55mm. As I write there are numerous copies of the second lens available for sale quite inexpensively. Indeed, some are mislabelled as "close focusing". But there is not one copy of the close focusing version available on the internet. It's a rare bird, and worth discussing. The Vivitar 135mm CF was manufactured by respected Japanese lens firm Komine between 1975-81. It is a solid piece of metal and glass with the unsurpassed build quality that is typical of that period. The rubber knurled focus area is wide and easy to use. The lens weighs 425g and is 86mm in length, but extends to 158mm at close distances. I'd recommend a tripod for close focus work, though all the shots here were taken handheld. The filter thread is 62mm and the front multicoated element does not rotate.The aperture is marked at 2.8, 4, 5.6, 8, 11, 16, and 22. There are half-click steps between each of these stops except for the last interval. It's easily to count clicks without looking at the lens. The iris has 8 blades and produces beautiful bokeh. Of course that's down to the focal length as much as anything. At 135mm and high magnification of the subject, almost anything behind the focal plane will be out of focus. Foliage presents a torture test (see image below). The optics includes only 4 elements in 4 groups. This is the Ernostar design developed by Ludwig Bertele way back in 1923! Add one more element and you get a classic Sonnar design, as this article explains. There is something so pure in knowing only four glass elements lie between you and your subject. At longer focal lengths such as this, you need nothing more for excellent optics. Though the design issues get more complex as the angle of view widens. The more that light must be bent before entering the camera, the more difficult the optical solution.  The helicoid has a long throw. One full revolution of the focus ring takes us from infinity focus to 1:3 magnification, this number clearly marked on the barrel behind the grip. Another half-turn takes us to the maximum magnification of 1:2. This gives us plenty of control in the near-macro range where we most need it. We can commend Vivitar on labelling this ability "close focus" and not "macro", since technically the latter requires 1:1 magnification. Most contemporary manufacturers cheat this definition. The closest focus distance is 59cm, which gives us a good distance between the front of the lens hood and our subject. This prevents the lens from casting a shadow on our subject, a problem with macro lenses in shorter focal lengths. The lens was available in several mounts including Canon FD, Nikon AI, Minolta MD, Pentax K, and M42. I have the latter. An inexpensive L-mount adapter allowed use on my Panasonic Lumix S5. As mentioned, the photos here were shot handheld. I used either f/4 or f/8. Though the lens is also sharp wide open, I find the DOF too shallow to be convenient.  I fitted a Nikon HN-23 hood to prevent flare.  All the photos are processed, not straight out of the camera. My intent was to demonstrate real-world use, not conduct a formal test. You can check out the original 2013 article (in two parts) which includes plenty of sample images taken using the Olympus PEN E-PL2. On that camera this lens acts effectively like a 270mm lens, and so is even more incredible! Back when I was first considering a 135mm lens for my Pentax camera I checked out the available offerings and realised that the close focus distance (around 1.5m) would be frustrating for my style of photography, which was often detail-oriented. Some nice alternatives to this lens are described in my previous article. But my favourite is the Vivitar 135mm f/2.8 Auto Telephoto Close Focusing.

The best and cheapest laptop you can buy (2024 edition)
If you are looking for an excellent lightweight laptop for everyday use, I have a suggestion. My impetus for writing this article is not to encourage you to spend more money, quite the opposite. My goal is to highlight a strategy to counter the continuing wastefulness of the tech industries. Read on for a (slight) rant and some (excellent) advice.  The problem: no improvements, more e-waste For about a decade now, new models of computers and components have been released in profusion with only incremental benefit.  On the desktop side we have a shining example in Nvidia. Their 4000 series graphics cards add little of note to the previous lines, but are nonetheless more expensive. The very fact they are "new" encourages gamers to upgrade from their perfectly-good current cards. Similarly, Intel CPUs of the 14th generation (Raptor Lake Refresh) are no faster than their predecessors. Indeed, we could go back to the 11th generation (Rocket Lake) without losing any features or performance that matters. Apple releases new iPhones that seem to differ from their last model only in how rounded the corners of the casing are.  Reviewers will point to a 10% increase here or a 20% benefit there, using metrics specifically designed to show such gains. But small numbers don't matter. A good rule of thumb is that one requires a 100% performance boost before the change is likely to be noticed in everyday usage. Turning to laptops specifically, the situation is similarly stale. Continued pressure from Apple sees functionality dropped in favour of producing the thinnest possible lifestyle accessory. As a design goal this has absolutely no advantages. Indeed, the restricted space inside the casing leads to overheating or the performance throttling that Apple has been known for.  A micro-thin laptop means ditching useful ports and features. For example, it's now rare to find an RJ45 port for Ethernet, since this is ever-so slightly too tall for the housing. We have been taught to use wireless internet, even with a router within easy reach. Even though wired internet is much faster, more reliable, and energy efficient.  Though the right-to-repair movement grows, especially in the USA, Windows/Linux laptops are following Apple in reducing user access to components. Granted, no manufacturers are as terrible as Apple in this regard, but it is now commonplace for RAM to be soldered to the motherboard. A few years ago it was still quite possible to buy a laptop that allowed a memory upgrade down the line, hence extending the useful life of the device. (My previous laptop was an example.) In short, laptops have become ever-more wasteful machines, exactly as environmental pressures on resources are amplifying. That's why I continue to buy laptops second-hand, keeping these units out of landfills, ensuring that perfectly good machines get used. As a bonus I get units that are at least as capable than those currently on offer... and often more flexible in terms of connectivity. Laptops (circa 2011) A decade ago (August 2014) I bought a refurbished Lenovo Thinkpad X220, upgraded the RAM to 8 GB, and replaced the hard drive with a fast SSD. Boom! A performant computer. This ancient model, dating to 2011, has since done duty as my music performance computer, pressed into service with an RME audio card and variety of MIDI controllers.  Despite the aging specifications, this model has served me well. Reviewers will tell you that you can't create electronic music on such an ancient device. Meanwhile I am out there using Reaktor and other synthesis programmes without a problem. But all good things come to an end... eventually. Recently the X220 has become a hindrance while travelling. The lack of contemporary ports (notably HDMI) has proven to be a liability at festivals and conferences. So, I set about finding a replacement. This process began with a short list of necessary features. Laptop shopping list (circa 2024) Since I already have a powerful desktop computer for media production, my requirements for a laptop are quite modest and mainstream. The picture would be quite different if I needed to game or produce video content while mobile. My first requirement is a generous supply of contemporary ports including HDMI, USB-C, and USB-A. Dongles be banished! Second, I need a laptop that can last all day on a battery charge. The weak battery life of the X220 meant that I needed to carry my AC adapter everywhere. But one area that has improved in the last decade is processor efficiency. The reduction in overall power consumption is better for the environment and allows longer periods between charging. Contemporary laptops have largely switched to using the USB-C port for power delivery. This relief from proprietary power bricks means that means that, in a pinch, any USB power adapter can be used for charging. Convenient! Third, I need something lighter than the X220, which weighed in at 1.7 kg, about the same as a contemporary Apple MacBook. That's too heavy for me.  Since the screen size of a portable laptop is only going to be around 13", high resolution is not desirable. If I want more screen space i will attach an external monitor. The current standard of FHD (1920×1080) is already an improvement over my existing computer. But a matte screen is essential... and increasingly difficult to find. Glossy screens make films look flashier but are a hindrance in all other use cases.  At a minimum I require the battery and SSD to be serviceable. This is especially important when buying an older unit, because these are the first things that might need an upgrade. It's a shame that I can no longer insist on upgradeable RAM, but so be it.  Speaking of which, I'd prefer a unit with 16 GB of memory, but honestly 8 GB RAM is also fine for daily tasks.  A good keyboard is a requirement. Similarly, it is essential to have a trackpad with physical buttons. This too is becoming increasingly rare. Why? I guess buttons break the sleek, clean lines of the chassis. Quiet operation is also necessary, since quite often I am focused on analytical or listening tasks. The only time I will be stressing the processor is when producing music, in which case the background noise of a fan will be masked anyway. Almost there. But there are still two more constraints. First, price. With the cost of daily living so high, I do not wish to drop two grand on a computer that is, for me, secondary to my custom-built desktop. Second, service. After reading countless reviews and forum posts I discovered that almost every major brand is disliked for their build quality, service, and support. Dell, HP, ASUS... they all seem equally poor once one gets past the glossy reviews. To summarise: 13" matte screen at around 1920×1080 resolution. Small and light, less than 1.4 kg.  Long battery life: 6h+ for daily tasks, 2h+ for synthesis.Serviceable battery and SSD essential. RAM nice too.  Minimum 8 GB RAM, preferably 16 GB.  Minimum 3 USB ports including both USB-C and USB-A. HDMI video and minijack audio.  USB-C charging. Good keyboard without layout compromises. Trackpad with physical buttons. Quiet operation.  Warranty: 1 year. Company with quality service record and known reliability.  Things I don't care about: Speaker quality. They are all rubbish anyway. Why do reviewers focus on this? I own headphones! Graphics performance. Won't be used for video editing or gaming. So, which laptop? This might seem like a ridiculously demanding list of features. But I am here to provide the impossible! After much research, I ended up back at Lenovo. Here I am guaranteed a good keyboard and trackpad. Plus, as a bonus, that excellent little Trackpoint that I find superior to a mouse. YMMV. But you have the option to use either pointing device... or both.  Like other companies, Lenovo have a confusing array of product lines. Of those that focus on portability, the pinnacles are the ThinkPad X1 Carbon and ThinkPad X1 Nano models. But these units are so small that performance and features are compromised in favour of style. Investigation revealed numerous complaints about DOA units or components that simply stopped working.  The "next best" portable product line are the ThinkPad X series. These are only slightly larger than the Carbon and Nano, but this (apparently) makes a significant difference to air flow and heat venting.  Oh, have you noticed? After weeks of deliberation I had now arrived back at the same conclusion I'd made a decade prior! A new ThinkPad X it will be.  Every year since the X220 a new model had been introduced, even if these changed only slightly over the previous iteration. In the last decade the lineage went like this: X250 (2015), X260 (2016), X270 (2017), X280 (2018), and X390 (2019). The line was then rethought as the X13 G4 (2023) which was crippled relative to the older X line. The ThinkPad X390 is the 10th generation of this product line, and the second-last model. So this looks like the best option to pursue, since it's just old enough to be available at refurbished prices.  The X390 has a 13.3" 1920×1080 matte screen of sufficient brightness and accuracy. At 31 x 22 x 1.7 cm and 1.22 kg the unit is compact and light. Consider that this is about 200g more than the lightest laptop on the market, but 500g less than my previous model.  The M.2 drive and battery are user serviceable. The computer runs cool and quiet for over 8 hours on a battery charge. At full steam a slight whirr of the out-take fan is audible. No fewer than four USB ports  are available, in a variety of configurations, including USB-C for power delivery. You can read a review at Notebook Check for more details.  I sourced a unit with 8 GB RAM and a small 256 GB SSD for €395 shipped. After upgrading the storage I will have a very capable computer at a quarter of the price of buying something new. (A similarly configured X13 is €1560.)Eventually I could have found a unit with 16 GB RAM. But most refurbished units are not configured with extra memory, so it might have taken some weeks of waiting. On this occasion I had a pressing deadline and a busy schedule.Here's the computer on my kitchen table, with my mobile phone (Samsung S23) for comparison.  Evaluation The 4-core Intel i5-8265U is an 8th gen (Whiskey Lake) CPU. But, as already stated, older is not necessarily worse. This model does support the H.265/HEVC video codec and 10-bit colour depth. DaVinci Resolve runs without complaint on this computer, though I wouldn't attempt more than simple editing. Nonetheless, it's good to know that I can view the assets I'll be shooting.  I ran Passmark against my other systems. The CPU benchmark is double my previous laptop, while the built-in graphics are a 500% improvement! This unit should last me another decade, while keeping yet another computer out of the landfill. I hope you will consider doing the same. About refurbished computers While it's perfectly possible to buy a used computer, locally or on eBay, this process is potentially risky. Some people may well have discovered a deficiency in their computer and wish to sell it on without revealing all the details to you. You have no guarantees.  A better alternative is to source a refurbished computer. These are available in two main ways. First, directly from the manufacturer as customer returns. These are often labelled as "factory outlet" stock. The price discount is usually only moderate.  For deeper discounts, turn to a third-party company dedicated to this task. These units are often lease-end stock from corporate environments. This is especially true for manufacturers like Lenovo and Dell, whose products are favoured in the corporate world. These units are generally like-new, perhaps with some small signs of wear. Any defective components are replaced, so there is no risk. A one-year warranty is typical.  Before Brexit I bought directly from such firms on eBay. For this recent purchase I used the site Refurb, which amalgamates listings from European refurbishing companies. My computer actually came from Spain. The only thing to watch out for is that the keyboard is in a language you can deal with. Thanks for reading this far. I'd love to hear from anyone else who follows a similar route. I do hope this article helps those on a budget obtain a useful tool for their productive lives!

Photographic Equivalence
The subject of image equivalence is often mis-represented as overly complex or (worse yet) a matter of opinion. This article will counter incorrect statements you might read elsewhere, while simplifying the subject for concision. References are provided for those who wish to delve further. 1. When is equivalence useful? Equivalence is important when comparing different sensors / film sizes / back planes / cartridges. There are three common cases: When comparing systems prior to purchase, in order to determine which best suits your needs.  When you own more than one camera system and wish to make a choice for the task at hand.  If you are cropping in to use a smaller portion of the available sensor, for example to get a higher frame rate when shooting video.  2. Defining equivalent images We define equivalent images as those that look identical. The key photographic/cinematographic parameters to we must equate are motion blur, perspective, angle of view, depth of field, and exposure.  Differences of sensor technology and other factors will introduce further distinctions between systems. Equivalence does not claim to equalise all such factors; that is not the aim.  3. Other optical factors Additional optical factors are critical to how an image looks but aren't included in the definition of equivalence, since they are not (significantly) impacted by the sensor size. These include the amount of detail, sharpness, contrast, vignetting, colour, bokeh, field distortion, image noise, coma, astigmatism, and other aberrations.  Matching lenses between different systems is a difficult, if not impossible, task. Again, equivalence does not claim to accomplish this.  4. Crop factor The ratio of the diagonal length of two sensor sizes is commonly called the "crop factor" (abbreviated CROP below). For some time 135 film (so-called "full frame") has been held as the standard, defined as the ratio of 1. Some people get quite annoyed by this arbitrary decision, but in fact we are free to compare any two systems and calculate the appropriate ratio. Way back in 2011 I argued that we should instead use the square root of the sensor area, since this takes into account different aspect ratios. Though I rather doubt that the industry is going to change its mind!  FORMAT SENSOR SIZE CROP 645 56.00 x 41.50 0.62 H3D 48.00 x 36.00 0.72 645D 44.00 x 33.00 0.79 35mm 36.00 x 24.00 1.00 APS-C 23.60 x 15.70 1.53 APS-CC 22.20 x 14.80 1.62 MFT 17.30 x 13.00 2.00 2/3" 8.80 x 6.60 3.93 1/1.63" 8.00 x 6.00 4.33 1/1.7" 7.60 x 5.70 4.55 1/2.3" 6.17 x 4.55 5.64 1/2.5" 5.76 x 4.29 6.02 APS-CC is my abbreviation (not a standard) for Canon's implementation of APS-C, which differs from all other manufacturers.Now we can consider the key photography parameters in turn.  5. Motion blur For still photography, motion blur is controlled by our shutter speed. Since shutter speed is not affected by sensor size, we hold this factor invariant to get equivalent images.  (For video, motion blur is a combination of our frame rate and shutter speed/angle, so we must also hold frame rate invariant for equivalence.) 6. Perspective Perspective is based on the position of the camera relative to subject and nothing else. Perspective is held equivalent by not changing our camera position.  The term compression is sometimes used when describing perspective affects. Since compression is a combination of perspective and angle of view (see next section), it need not be considered independently of those two factors. The term is redundant. 7. Angle of view The angle of view (AoV) is the angular extent of the imaged scene. The term "field of view" is sometimes used as a synonym, but at other times as a distance measure, so I'll stick with the more correct term. AoV is based on the ratio of focal length (f) to diagonal sensor size (s).  The actual equation is AoV = 2 * arctan(s / 2f). We can match AoV for different systems (indicated using subscripts) by equating the ratios within the function. Hence, s1 / s2 =  f1 / f2. From section 4 the ratio of sensor sizes is the crop factor, so s1 / s2 = CROP. Substituting, we get f1 = CROP * f2. Conclusion: To find the focal length that results in an equivalent angle of view, multiply the existing focal length by the crop factor. 8. Depth of field DoF is a subjective description of how much of a subject is in focus. In truth, a given lens can only perfectly focus the subject at one precise distance. At every other distance, objects are out of focus. What matters is how much objects are out of focus. This is measured using the blur circle, specified by the ratio of aperture diameter (the entrance pupil) to subject distance. But since we are maintaining the same distance to subject (for equivalent perspective) the blur circle is proportional only to the aperture diameter. Photographers rarely know the aperture diameter (a) of their lens. Instead, this quantity is specified by the f-stop (p), calculated by dividing focal length by the aperture (p = f / a). Rewriting this as a = f / p we can ensure the same blur circle by equating apertures on the two systems. Hence f1 / p1 = f2 / p2. Substituting in the equation from the previous section gives us p1 = CROP * p2. Conclusion: To find the f-stop that results in the equivalent depth of field, multiply the existing f-stop by the crop factor. 9. Exposure At this point our two images are shot using the same shutter speed (section 5) but different apertures (section 8). To ensure identical exposure, we must increase the ISO of the larger sensor camera by that same crop factor. While this might add more noise to our image, it is generally true that larger sensors are better at handling noise. So in practice this difference is not significant. In any case, noise is an image quality factor, not a matter of image equivalence as such. 10. In summary: our recipe To maintain image equivalence between two sensors: Multiply focal length by the crop factor. Multiply f-stop by the crop factor. (Or add the crop factor in stops to the f-stop value, since this is the same operation). Add the crop factor in stops to ISO.Maintain the same perspective (distance to subject). Maintain the same shutter speed/angle.  11. Examples Two examples will make these relationships plain. The following will produce equivalent images, all else being invariant. One can readily find lenses that will allow this equivalence.  MFT: 25mm f/1.4 ISO 200 APS-C: 33mm f/1.8 ISO 320 FF: 50mm f/2.8 ISO 800 What about a standard portrait lens? Fulfilling this criteria with a smaller sensor is quite difficult. MFT: 42mm f/0.9 ISO 400 APS-C: 56mm f/1.2 ISO 700 FF: 85mm f/1.8 ISO 1600 The following table presents equivalent focal lengths for three systems, including these common focal lengths for each: 18, 24, 28, 35, 50, 85. This can be handy for quick look-ups. MFT APS-C FF 9 12 18 12 16 24 14 18 28 17 23 35 18 24 36 21 28 42 24 32 48 25 33 50 26 35 53 28 38 56 35 46 70 37 50 75 42 56 85 45 60 90 50 66 100 64 85 128 85 113 170 12. Finally Equivalence is an intriguing concept that can shed light on how different photographic properties interact. It's essential knowledge in several recurring situations where you need to match stills or video footage shot on different systems. I trust that this article has provided a clear and concise overview of a topic that is often over-complicated. 13. References Wikipedia articles are not necessarily written for clarity but do contain equations for crop factor, circle of confusion, and image sensor format.  Steve Yedlin, ASC has some clearly articulated reasoning similar to my own.  Joseph James has rather over-long and detailed coverage. Tony & Chelsea Northrup provide a simple video demonstration, though with some imprecise use of terminology.Updates6 July 2024: Significant edits for clarity

Martha Graham on artistic vitality
“There is a vitality, a life force, an energy, a quickening...”  This fantastic quote from Martha Graham is reproduced below in its entirety, together with correct reference. Provided as a resource for those who see this distributed on social media.  The following passage can be found in Agnes De Mille's Martha: The Life and Work of Martha Graham (New York: Random House, 1991), p. 264. The greatest thing she ever said to me was in 1943 after the opening of Oklahoma!, when I suddenly had unexpected, flamboyant success for a work I thought was only fairly good, after years of neglect for work I thought was fine. I was bewildered and worried that my entire scale of values was untrustworthy. I talked to Martha. I remember the conversation well. It was in a Schrafft’s restaurant over a soda. I confessed that I had a burning desire to be excellent but no faith that I could be. Martha said to me, very quietly, “There is a vitality, a life force, an energy, a quickening that is translated through you into action, and because there is only one of you in all of time, this expression is unique. And if you block it, it will never exist through any other medium and it will be lost. The world will not have it. It is not your business to determine how good it is nor how valuable nor how it compares with other expressions. It is your business to keep it yours clearly and directly, to keep the channel open. You do not even have to believe in yourself or your work. You have to keep yourself open and aware to the urges that motivate you. Keep the channel open. As for you, Agnes, you have a peculiar and unusual gift, and you have so far used about one-third of your talent.” “But,” I said, “when I see my work I take for granted what other people value in it. I see only its ineptitude, inorganic flaws, and crudities. I am not pleased or satisfied.” “No artist is pleased.”“But then there is no satisfaction?”“No satisfaction whatever at any time,” she cried out passionately. “There is only a queer divine dissatisfaction, a blessed unrest that keeps us marching and makes us more alive than the others.”

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