6.21.2021

The Clash of Titanic Lens Design Philosophies. Modern versus the quest for perfection.

this is a Lastolite 4 x 6 foot diffusion panel. I use it a lot in the studio.
Right now, during the heat wave, I'm using it to block the strong afternoon
 sun from a direct assault on my living room. It seems like the right tool for the job today.

All lenses are baskets of compromise. It seems that every generation of lens designer is concerned with a different set of variables and outcomes than proceeding designers and understanding this is key to becoming immune to what are almost certainly transient styles in the look given by lenses rather than a sign of radical improvement in the overall quality of them as products. 

I noticed, for example, that with the current big, heavy, fast primes, that the primary objectives seem to be the delivery of lenses with sharpness that extends further across the frames and into the corners, at full aperture, when compared with previous offerings.

By making lenses which feature bigger and bigger maximum apertures, with flat fields, buyers are accepting the trade-offs of having lenses that are much bigger and much heavier than the smaller, slower lenses which were more normal in the past. It's ironic since camera buyers of today are demanding smaller and lighter  cameras than ever before; almost as if a rush to zero weight is somehow a benefit, but one profoundly offset by their lens purchases.

If I compare sizes between f1.4 lenses for mirrorless cameras and equivalent lenses made for SLRs from the 1980's and 1990's it's easy to see that sizes have increased by a lot. I own a handful of manually focusing 50mm f1.4 lenses, acquired over decades, and it's only in the past ten years that they've ballooned up huge, and also graduated to a much higher weight class. Of course, some of this is the result of adding robust auto focusing mechanisms to the newer lenses but it doesn't tell the whole story. 

Older lenses, according to literature I've read, were knowingly designed to be very sharp in the central region, adequately sharp in the middle regions of the frame and allowed, by design parameter, to become less sharp in the corners; at least when used at maximum apertures or close to maximum aperture. 

Knowledgeable photographers who actually needed "flat field" lenses knowingly bought macro lenses which were corrected for flat fields if they needed to shoot flat subjects such as paintings or the sides of houses. But by allowing for less sharp corners didn't mean a lens was less capable. If a well designed lens from the end days of the last century needs to be used to photograph a flat subject much of the time stopping down to f5.6 or f8.0 will render the entire frame with high sharpness. Even the corners. The positive trade off for older designs versus the latest designs is that the previous generation of lenses was constructed to be used in the field; they are small and light enough to be easily transported and more discreet in operation. Having to stop down for so incidences was part of an acknowledged bargain. 

The new generation of large, prime lenses with high speed apertures has ushered in lenses that use 67-82 mm filters and are, as in the case of the Panasonic S-Pro 50mm f1.4, about overall the volume of my Canon, Nikon and Contax Zeiss 50mm f1.4 lenses combined. And the newer lens is actually heavier than all three of them taken together. Yes, it is razor sharp at f1.4, all the way into the corners. Do I shoot it in that mode? Hardly ever. 

As I look at current lens measurements and compare them with older lenses of the same overall parameters (focal length+speed) I note that while the older lenses have sharpness fall off (mostly as a result of lens curvature) from center to corner they compensate by having less geometric distortion and much less vignetting. Since it was impossible to fix lens design compromises, after the fact, with film cameras (no software on film!) the older lenses were designed with the fewest image-oriented compromises. Today, a $5,000, 50mm f1.4 lens might have as much as three stops of vignetting at maximum aperture while a classic lens might only have 1.25%. Yes, on modern cameras, it's possible to correct for each compromise via in camera software but if you want to use older cameras or adapt the new lenses to different platforms you lose some of the advantages you are paying through the nose for. 

Many 50mm lenses of previous generations had simple barrel or pincushion distortion which is easily correctable in post processing while their modern successors have more complex distortion profiles (some called "mustache" distortion) which are much harder to correct in post processing software; outside the current cameras. 

As all of our lenses grow in size and weight, and escalate in price, the real question is whether or not they are visually as pleasant in the final rendering of an images as are the lenses we grew up with, pre-digital. I contend that as they technically became more and more "proficient" they've lost their individual character. Their optical fingerprints which made some lenses long time favorites. Keepers. Gems.

The real question is whether the trade-offs are working to your advantage. I am a portrait photographer. I'm happy to have a bit of sharpness fall offs in the corners of my images because my subjects are in the sweet spots of the imaging circle and the lowered sharpness of the corners is a pleasant way of further separating the sharper subjects from the less sharp backgrounds. 

You must also realize that along with the increases in pricing, etc. you are getting lenses that you are less and less likely to feel comfortable hauling around with you and practicing styles of photography that rely on your mobility and your ability to respond to scenes without too much pre-planning. And to do so inconspicuously. I question whether any but the most driven camera technicians are comfortable hauling around gargantuan lenses while mostly using only a fraction of their potential performance. 

I don't think that lens designers pursued the designs they've recently opted for in a vacuum. I don't think some head designer came in and told his team, "from now on we're emphasizing lens speed over package size." And then foisted the results on unsuspecting consumers. Rather, I think the constraints for the first three or four generations of widely accepted, interchangeable lens camera systems drove consumers to demand more speed. Why? Because, in case you forgot, the first ten years of popular digital camera featured sensors that were very, very noisy at any but their base ISOs. To compensate for lots of icky color noise at ISO 400 or 800 camera makers pressed their teams to make faster and faster lenses. Since camera users wanted cleaner files they went along for the ride. 

It's all pretty ironic since photographers seemed to be able to handle photographing with slower film emulsions and less over-designed lenses in the last years of the last century. Most of the faster lenses in those days were designed to overcome the viewing and focusing limitations of earlier optical viewfinder cameras. As light dropped it became harder and harder to focus on the focusing screens of the time so users bought the faster lenses in order to put more light onto the screens and to focus at those brighter, maximum apertures and then stop down, or let the cameras automatically stop down, to a smaller shooting aperture that made for better overall picture quality. The limited depth of field as a result of focusing wide open helped accentuate what was in focus and what was not.

An interesting question would be whether or not the faster current lenses, with wide open apertures, drove the pictorial style of using very shallow depth of field or if that style was always there, in potential, but only realized as a result of lens "progress." 

Now that the race for less noisy digital camera sensors seems to have been won by new sensor tech from Sony and others it will be interesting to see if there is a reverse trend back to more compact and size appropriate lens development. The Sigma i Series of f2.0 prime, Contemporary lenses sure points to this direction --- and is being quickly copied by Sony...and others. 

Another point of interest for me is whether the ability to put lens profiles into camera software is driving lens design or not. I think of the choices Leica seems to be making with their SL lens line. They seem to be designing for flat field and high resolution. The files I see from their systems are both contrasty and highly detailed but I wonder how much of the mix is driven by the in camera or lens-delivered processing software which optimizes the final, visual performance of the lenses. 

It's hard to design for both high contrast and high resolution simultaneously but while resolution is mostly determined by the physical properties of the lens design and construction while contrast, and even micro contrast, can be augmented with really good software or firmware design. Contrast can be ramped according to taste and branded, engineered looks. The higher the basic resolution the more micro-contrast can be tweaked in camera. But in the absence of an in-camera or post "look" or "lens profile" do the lenses still deliver the goods? I haven't tried it with a contemporary Leica lens but it would be interesting to use one on a camera, in a raw format, with no profile applied. I would conjecture that the lenses would still deliver high resolution and corner sharpness but the color and contrast would be different and perhaps less distinct from very similar, competitors' products. 

I would also presume that while the sharpness and detail would be maintained that in the absence of the embedded profiles the images straight out of camera would show higher degrees of both distortion and vignetting. In wider lenses to an even greater degree. 

Which brings me back to why I tumbled down this rabbit hole in the first place. Last week I'd taken the Sigma 35mm Art lens for L-mount out on a photo walk and worked at what I consider to be its most favorable aperture (if you are looking for the least vignetting, the highest sharpness, the least computational correction, etc.) which most published tests indicate is around f4.0. The photographs were uniformly great. Sharp, contrasty and with very nice, saturated colors. 

I did the same basic routine yesterday with the much more traditional, older, much smaller and lighter, and one stop slower, Zeiss ZF 35mm f2.0. While each lens delivered a different "look" the technical performance results were amazingly similar. They presented files that are equally sharp, and equally detailed. Even at 200% there are scant differences in the amounts of detail rendered. One defining difference was the more airy and open feel of the Zeiss lens. Not a significant difference but enough to make me realize that even in this age of being able to measure everything there are different "characters" associated with different lenses.

I'm sure if I had tried each lens at f2.0 the Zeiss would not resolve corners as well. And, as I got closer and closer to a flat surface subject I'm sure the gradation from sharp to soft; center-to-corner would grow demonstrably worse. The Sigma would outperform in that test. But does that make it the uncontested winner if your use case is to carry a 35mm lens with you everywhere and to shoot mostly at f4.0 and f5.6? Would the nearly twice as heavy, and 50% bigger, Sigma still hold your affections to the same degree?

And that, my friends, is lens design compromise in a nutshell. 

The most glaring examples of over-design versus pleasant handling and look trade-offs come via a comparison of two products of close to the same focal length from one Company. Sigma has a 40mm f1.4 Art lens that's enormous and brutally heavy. I venture to say that a person working, handheld, with one of these would toss in the towel after half an hour of carrying it around. Overwrought is the word that comes to mind...

In contrast Sigma also makes a 45mm f2.8 lens that's small, light weight and a joy to carry around. The use cases are phenomenally different but is one lens "better" than the other? And how does the potential of the camera and the lens profiles factor in? I voted, rationally, with my credit card, I have two of the 45mm f2.8 lenses and zero of the giant 40mm f1.4 Art lenses. While there might be ten or fifteen times in a year that I could even make use of a 40mm, shot wide open, there are daily cases when I can and do happily use a 45mm f2.8 lens stopped down to f5.6. I've never given any consideration to spending a thousand dollars more, or getting a gym membership so I can train to power lift a lens. 

The compromises in lens design are partly (mostly?) a result of consumers clamoring for what they think they want in order to solve a technical problem in the moment. The longer term issue comes with the amount of time it takes to design and deliver a new style of product to market. In the case of lenses many of the high speed lenses hit the market only after the sensor noise issues were largely solved. 

I personally like lenses with high center sharpness and I'm always pretty happy to trade extravagant resolution and flat field for more image contrast and less native distortion. And I'm even happier to have lenses that need to be physically focused because they don't contribute to battery drain or laziness. But an even higher priority is a lens that's easy and fun to carry.

Let's tackle image stabilization next time. Thanks for reading,  Kirk
Blanton Museum. Sculpture in the upstairs gallery. 
S1R in monochrome. 

Ellsworth Kelly Chapel at UT Austin.







 

Moving on to "Father's Day Lens Gifts." Anybody get some?


For some reason Father's Day was a blast this year. I slept in. I made perfect coffee. Belinda made my favorite chocolate cake with walnuts. The Father's Day cards were perfect and hilarious. Ben was in charge of dinner and made ridiculously good New York Strip Steaks exactly medium rare, diet-busting macaroni and cheese, and a salad with a hint of BBQ taste to it. He paired the extravagant dinner with a bottle of Leviathan red wine (an insanely good blend...) and lured me off my "no alcohol" stance for just one day. And it was worth it...

All that was great but I also gave myself permission to pick out (and pay for) my own Father's Day present, you know, to reward myself for all the hard work I do for the family (highest degree of sarcasm intended, the whole place seems to have settled into running well on auto-pilot). So, after a spartan lunch (anticipating supper) I headed over to my favorite optical candy shop to pick up a lens I'd seen languishing on the shelves for the last couple of months. 

Backtracking: Carl Zeiss, the lens making company that routinely gives Leica a run for the money, made some fun and interesting lenses back closer to the turn of the century. They came out with a series of lenses with mounts for Nikon F, Canon EOS and Pentax K in a range of focal lengths and maximum apertures. Many are still available new! All were made initially as "dumb" lenses, later updated to interface with metering in the Canons and Nikons but all were realized as manual focusing only lenses. In the days of DSLRs they were harder to focus via the optical viewfinders in the various cameras (focusing screens optimized for bright viewing and AF, NOT for careful manual focusing). Mirrorless cameras have changed all that by offering easy ways to magnify the frame while focusing which makes for quicker and more accurate focus. Most mirrorless cameras even feature focus peaking for quicker street photography focusing action. 

I tried their 85mm f1.4 lens years ago but it was on a Nikon D800 and focusing was always hit and miss. I gave up and bought a Nikon AF 85 instead but still remember how nice the images from the massive Zeiss lens were when all the photo gods allowed random moments of precise focusing...

I'd seen this poor, orphaned Zeiss 35mm f2.0 ZF (Nikon) lens moping dejectedly at Precision Camera weeks or months ago. It seems as though most photographers had given up on DSLRs and were overlooking a lens that couldn't be used with AF or, without an adapter, on a Z body. I walked in on Sunday afternoon and snapped it up. I already had several Nikon to L-mount adapters on standby so I rigged it up, slapped it on a Panasonic S1R and ventured out into the smothering heat and humidity and tested it out to see if it was as good as I remembered the good photographers saying it was, back in the day. 

It's a great lens. I like the character of it even better than the Sigma 35mm f1.4 Art lens I have been shooting with. And I almost always prefer manual focusing; it's so engaging. I feel like I'm actually participating in the process of making photographs!

This lens joins a little family of Zeiss lenses that I've collected over the years. The others were all made for the Contax/Yashica system but the look of the images has family resemblances. Snappy contrast, lower native distortion and vignetting than more "modern" lenses and a range of optical trade-offs that are different than current lens design philosophies. I like them. All of them. 

The lens was inexpensive and worked perfectly in "A" mode with the Panasonic S1R camera. All the images were shot as medium resolution Jpegs (about 23 megapixels) and very lightly processed. Generally just a mild lifting of the shadows. 

I've moved the lens over to one of the Leica SLs now and I'm waiting for the heat to break before doing a daylong dive into the combo. I'm thinking a shooting trip to San Antonio is called for. Might as well get out of town for a day of street photography. Now I just need to carve out time...











My new friend, Ajax. Just chilling with one of his pals on 2nd St. 




 Please consider clicking on these images to see them bigger instead of clicking on some links to buy stuff.

If you happened to reward yourself, or better yet were rewarded for good Father behavior by someone else, with any sort of lens, I'd be interested in reading about it. Let me know. 

till then I'm zoning out with my cameras.

Critical Summer (and winter) Photo Gear: Hats.

 


Tax policy, the best tasting beer, the right way to do a flip turn, the best show on Netflix, the proper temperature at which to serve Chardonnay, favorite color, favorite sport. You can reasonably argue about these things and not seem deranged but start a conversation among photographers about which hats to wear while working outdoors and, my friends, you have opened a can of worms that will turn ugly quick. 

I won't say I got death threats after denouncing the "Tilley-Ugly-Hat" phenomenon but I did get some heated e-mail. Imagine having time to rush to the defense of a hat which, sartorially, doesn't fit in anywhere and currently costs about $90. It just doesn't make sense. And while the "Tilley" is silly because of the cost-to-performance ratio, and the general look, it just gets called out because it's a lightning rod for a plethora of poorly chosen hats. 

Case in point (and modeled here by VSLs most attractive employee) are the ubiquitous bucket hats. It's hard to make a case for these. But I'll pause here and say, unequivocally, that if you are working in the sun I'd rather you wear any of these hats and have the protection on the tops of your ears, your scalps and most of your face than not to wear a hat at all. It's just that you can to better. 

I'll agree with many that have written in that, if you are retired and happily married, you can wear whatever hat you want to and, even if it is a public eyesore, it's nobody's business but yours. But if you are currently trying to attract a mate or a job you may find that an ugly hat is a good way to stay single and underemployed. It's my sad duty to tell you that, in most situations, the way things look matters almost as much as the way things work. And it's important to understand that there are much more attractive hats on the market which also function just as well. Take a friend with a good sense of fashion along with you when you shop. Let them have veto power over your worst instincts. Find the guy from your past who talked you out of buying that Yugo you thought was a "nifty" bargain. Or take the old girlfriend who talked you out of buying the polyester leisure suit back in the 1970's. And the platform Dingo boots. 

If you want to buy a hat that is functional and also decent to look at take along a "lifeguard" to deter your worst instincts, like the room mate who cautioned you against giving up and buying only pants with elastic waistbands. 

I keep this bucket hat (see pix above and below) around as a reminder that things can always get worse. It's also fun to put on in order to tease my millennial son. But even someone as clueless as me would never presume to wear this around a client... it's a sheer business repellant.

To summarize: It's good and smart to wear a hat in the Summer. It's better to wear a hat that provides shade for the back of your neck and the tops of your ears so a wide brim is preferred. Skin cancer is serious; if you have no other option then the Tilley hat or bucket hat is so much better than no hat at all. Wear one until you have time to shop for something better. And then buy it. 

The only option where a poorly chosen hat is welcome is if all your time is spent fishing, hiking (in the wild), mountain climbing or any activity that joins you with other people in your niche demographic. Then, it's probably just fine to wear Dad Meme Hats. The rest of the time, and especially around people of all different ages, let's try to have a little pride in appearance. Won't you help the world look just a little better?

By the way, the Tilley hat people have a sales pitch which includes the fact that their hats float if they get dropped onto the water. I'm sure that many who receive them as unwanted gifts wish that they did not float...it would spare so many hurt feelings. 
Of course, I am mostly kidding here. I think that the protection a hat provides is 95% of its relevance. I really don't care which hat people wear. There will always be differences in taste. And different use cases. I was being silly when I wrote this but I always do wear some kind of protective hat whenever I'm out in the Texas sun; Summer or Winter. As global warming marches on and gets stronger and stronger we may as well start stocking in a variety of hats. Then we can choose the right hat for the right situation. 

The fact that I even own a bucket hat should prove I'm (mostly) just teasing about hats photographers of a certain age seem to gravitate towards. But, as a friend said recently, 'the Tilley Hat is the Black Rapid Strap of photo hats'. Goes perfectly with the photo vest and the fanny pack. One step from "crazy uncle" status.