The Visual Science Lab

Sunday, March 22, 2026

On Topic for some. Off topic for lots of others. If you own one of the APO SL prime lenses for your Leica SL(x) camera this is for you.

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Here's the 411...

When I got my copy of the Leica 50mm APO Summicron SL I was delighted with just about every aspect of the lens. There was one glitch which seemed to show up most on my very recent SL2-S. When I used the lens I would look through the EVF or look at a preview image to judge the exposure of the frame I wanted to take. With everything looking perfect and the histogram right where it was supposed to be I would take the frame. When I reviewed the image I had just taken it was invariably about a stop lighter than what I saw on the LCD or the EVF. It was weird. And incredibly frustrating.

I reset the camera, checked each individual line item in the menu to see if I'd mis-set anything and started all over again. The engineering part of my brain suggested I change out lenses and see if the behavior changed. With a Leica 24-90mm Elmarit Zoom the issue didn't show up. I decided to switch out camera bodies. I put the 50mm lens on a Leica SL. I didn't see the same issue. But on both the SL2 cameras I was able to repeat the sequence and the problem I'd seen with the the SL2-S. A one stop overexposure when compared to the preview image.

I could have gone down three paths. Send the lens back to the seller with a note. Endlessly trouble-shoot the problem until I fried my own brain and frustration overwhelmed me. Or, I could just see if this was a widely reported problem, check the lens and camera firmware, and then see if Leica had delivered updated firmware for the camera and the lens.

Being lazy and largely unmotivated to work on problems that are someone else's ultimate responsibility I chose to begin with door #3. Check on firmware updates.

Bingo. The lens was at firmware 4.0. The Leica site showed new, updated firmware for all of the SL APO primes. From the 21mm all the way up to the 90mm. And all could be updated to the latest firmware, 4.1, at the same time from one .plf file. And the reason for the update? Leica discovered that the lenses were delivering final images that were one stop brighter than the original preview images. In other words, the lenses were at fault. The lenses were delivering inaccurate exposure information or aperture information to the cameras. Regardless if you were shooting in raw or Jpeg.

I downloaded the file and updated the new firmware (4.1) for the lenses. Now, if I use the 50 APO SL on any of my other cameras the new firmware will be resident in the lens and shared with the camera in use. Alternately, I could update the firmware in each camera body. I would probably find this a better solution if I had more than one APO SL lens.

Did I test it to see if the update worked? Naw. I took a nap, went for a walk, had coffee, watched TV, read a Sony camera user manual for six hours, and went to bed. Right.... As if....

Reality: I immediately tested the camera and the lens together and found the problem had vanished and everything is working just as it's supposed to. Phew.

I did update the camera firmware from 6.0 to 6.1 but I don't think it changes much. The info provided suggests that the only thing that changed is some boilerplate legal language about compatibility with legal information. Not a big enough deal to worry about. But deep in the notes it does suggest that updating the camera firmware will also, automatically, update the APO lens family firmware so maybe I took one step I really didn't need to.

But it sure is fun having the lens work with the camera perfectly instead of me having to come up with the arduous workaround of using my brain to calculate the difference in image brightnesses and then factor that into the final shot with exposure compensation controls... Not really what I bought a pricy camera and lens for.

Happy that Leica came through with a fix. Fix yours if you have em.

Kirk out.

Saturday, March 21, 2026

Just rummaging around in some hard drives, looking at images from across the years. Happy to see that I still like most of the portraits we made.

Portraits are hard because it's never totally about how smart the photographer is or how wonderful his collection of cameras and lights might be. It's never about his incredibly clever ideas. Nope. A good portrait is always a collaboration. A sharing. A give and take. It's kind of a Zen thing to be patient enough to wait for the "stock" look to warm into an expression of trust and authentic expression.

A famous photographer once said that the secret to making a beautiful portrait is to fall in love, even just a little bit and only for the moment, with the person in front of your camera. I'll go with that.

This is just a random collection I found in a folder. I'm assuming it's something I put together for a gallery but I don't know if we ever used it that way. That doesn't mean I like the images any less.

M. Brilliant UT Student. Part time advertising model.

Realtor.

Professional talent in NYC

for the Zach Theatre musical, "Aida"

Chef Alma. Current restaurants: El Alma on Barton Springs Road and El Alma in South Austin

Amy.

Smoking optional restaurant owner. At the "Y" in Oak Hill. (film).

JV Capitolist

Aurea CEO

Management. A nationwide printing company

Austin Actor. He's been in everything. Wonderful to work with.

Breakthrough Student.

President Bill.

Danny Young. Music lover and restauranteur.

model for a dermatology practice. So sweet.

Psychologist.

David Garrido. Chef. Restauranteur.

Magazine model.

From the Zach Theatre production of Janis.

My first choice for one of my book covers. Sadly overruled by the publisher.

Austin Mayor, Kirk Watson. From way, way back after his first term.

Fellow photographer. Met up in NYC

Heidi. Primary model for my second book.

Martin Burke. My vote for best Austin actor .... ever.

Perennial Muse. Lou.

Meredith for Austin Lyric Opera.

Merlin Tuttle. Founder of the Austin Bat Conservancy.

Young parade goer.

Model for early digital furniture store shoot. Chrysta.

Penny. Baker. Business owner.

Sarah. Artist. Painter.

Renae. Amazing and irreplaceable assistant.

Sarah. Painter.

Student for Kipp School Annual report (Gold Addy Award winner).

And, of course, Noellia.

Fall 1978. England, France, Italy, Greece and Switzerland. Mostly camping and living out of backpacks. First foray with a good camera.

The Original.

Just add Tri-X film...

I wrote a piece yesterday that touched on the camera that really got me started down the path into the labyrinth of photography; the Canon QL 17-GIII. A "point and shoot" camera introduced by Canon in the mid-1970s. The last, I think, of a line of solid, built from all metal parts, fixed lens, prime lens, film cameras. The classic "compact" camera. If you've read the blog for a while you've probably read instances where I have mentioned it in the past. There is a reason for my nostalgia. That camera brought me enough good frames, with Tri-X black and white film, on an extended trip to Europe, to have inflamed and then cemented my sheer love of photography. And also pushed me into learning how to print black and white images in an actual darkroom. Gosh I miss Ilfobrom double weight, fiber photo printing paper. Grade 3, please.

The QL 17-GIII was a film camera that was quick and nearly foolproof to load film into. It wasn't small enough to be considered pocketable, unless you are a giant with absurdly enormous pants pockets, and it was reliable almost to a fault. The 40mm lens was/is sharp. But not too sharp. It was absolutely the perfect camera for a new, untrained, young, flustered, beginner photographer to bring along on one of those 1970's styled trips of a lifetime.

On my last commercial job, back in August 2025, I shot about 1,800 forty-seven megapixel raw files in one long, hot day. Digital, of course. But back in the Fall of 1978, when I was packing for a trip that would last almost a full semester, I thought that maybe 25 rolls of mostly hand-loaded rolls of Tri-X black and white film would suffice for the duration of the trip. About 900 shots, total, for months of travel and photographing. But it seemed, for all intents and purposes, to have worked out just fine...

If we want to discuss camera reliability I would have to say that of all the cameras I've owned that I came to trust the little Canon more than any other. Part of the reason is that I have had and used the camera (as you can see in the photo above) for something like 49 years. Not once has the camera so much as burped. The uncomplicated little leaf shutter keeps clicking away. The rudimentary rangefinder, while fading a bit, is still viewable and accurate. The moving frame lines in the finder do a good good preventing parallax induced compositional errors when the camera is used near the camera's close focusing distance. The camera is also considered by me to be reliable because if the battery for the meter and metering system fail entirely, and I'm in a location where a new battery is hard to find, the camera is still completely shoot-able. I'll have to figure out the approximate correct exposure but, for decades, in the studio, I used external light meters for light measurements so that's one work around. The other is that when shooting outside on a known film stock, between the hours of say, nine a.m. to about five p.m., the light isn't that hard to read. The Sunny Sixteen rule can be used. A memory of Kodak's little paper film exposure guides that came packed, back then, with every roll of film were a great way of getting into the exposure ballpark. And then there is film latitude. So, just think, after the nuclear EMP blasts in the upper atmosphere destroy all electronic circuits, I'll still be able to take images of the ever-mutating, remaining human population with my 50 year old camera. I'll just have to do the metering in my head.

This trip (1978) coincided with the widespread adoption of the Boeing 747 as the long haul airplane of choice for nearly all carriers so I often match the camera and that jet in my memory, of having belonged to my "golden age" of international travel. It was so, so, so easy back then. No phone. No credit cards. Only American Express Traveller's Cheques. And some non-domestic cash drawn from a local bank before leaving town. This far, far pre-dated the Euro currency so one needed to jump between different currencies in Europe as one travelled from country to country. It was fun to go cash traveller's cheques in Paris since the American Express office was right by the famous Opera House. And the Amex office has super good restrooms... and maps. Remember, since there were no cellphones one also needed paper maps to navigate a city or country. Interesting times. And having been a Boy Scout I did have a magnetic compass with us as well.

It was early days for me as a photographer. My majors at the University were anything but "art." I knew enough from quickly reading books and magazines before traveling that some f-stops were better for some things while other f-stops were good for...different other things. I had a photographer friend, a professional, whose main advice was to try not to shoot with a shutter speed under 1/125th of a second. Flash? Please.... I was having enough trouble getting stuff in focus and trying to remember what ASA meant--- and how to use that information.

When I came back to the U.S. with scruffy hair and an outrageous beard I read Ansel Adam's books and the Time/Life photo series of books and, with a little help from an older photographer, I learned how to develop four rolls of black and white film in one go, in a metal developing tank. And just like everyone else back then I initially had troubles loading the film on those metal reels that seemed to have been invented with the intention of making some parts of your film stick to and destroy the images on other parts of your film. But I practiced on less important film until I got the hang of it and then spent the next few months souping film and then painstakingly printing my images from the trip onto 8x10 inch photo paper. The good, pre-resin coated, double-weight fiber stock. The good stuff. Back when it was as cheap as free.

If one is traveling and learning photography at the same time I would advise that it's a good idea to bring along a sweet, cute, photogenic companion for the trip. (choose any two?). Traveling together 24 hours per day and sometimes sharing a small tent in remote mountain pastures or beside rushing river is a good exercise in fostering compatibility or.... completely ruining your long term relationship. But, at least you'll have someone reliable as a subject.

There is something to be said for inexperience and the inability to change cameras at will. You learn what works and what doesn't. You don't distract yourself much with the process and, since in those days there was no image review, no menus, no rear screen, no fine-tuning adjustments in the non-existent menus, there wasn't much on a camera to distract you. Which was nice. You just adjusted the exposure, focused and then put the camera down and soaked in the scenery.

The images below were all done while traveling with CanonQL17 GIII. It was a wonderful traveling companion. A good picture taker and quick to forgive me for my technical errors through something we called "film latitude." Maybe we have not come so far after all.