Calibrating New Glass to a Fotoman 6×17 Lens Cone: Part Two

In Part One, Fitting New Glass to a Fotoman 6×17 Lens Cone, I left off after successfully mounting the Nikkor SW 90mm f/4.5 to the lens cone and confirming infinity focus. This was only possible after removing the spacer that had been necessary for the Fujinon SW 90mm f/8. With the spacer gone, I also needed to order new nylon screws to secure everything properly. Infinity focus was achieved, and from there, I moved on to calibrating the lens for hyperfocal distance shooting—a technique I regularly use with this camera.

I reviewed Fotoman’s instructions and followed the steps carefully, taking cell phone photos to document my settings along the way. I chose to do the initial focus calibration out in the field. The film results looked promising (images 1 and 2 below), but I wanted to run one final test—this time calibrating the lens just outside my front door, using the foyer area as my setup point.

Why there? Simple: I could use the brick wall that leads from the door to the steps for close-range focus and then look across the street to the tree-filled yards and rooftops for distant focus. Using the ground glass and setting the lens to f/22, I confirmed hyperfocal focus not just with the distance scale but also visually. Unlike in the first calibration test, I did not have the wind or a limited area in which to place my tripod.

Initial Lens Calibration Tests for Fotoman 6×17

In addition to testing the lens calibration, I’m also using the AGO film processor for the first time with these rolls—a topic I’ll cover in a separate article soon. I did have one mishap (entirely my fault), which resulted in a partial processing failure on the second roll I processed. I didn’t lose the images completely, but there wasn’t quite enough developer in the tank, leaving the negatives weak, so I won’t be showing those. However, here are two frames that turned out just fine from the first roll.

Note: I processed the two rolls separately on purpose. When working with new gear, I like to take advantage of the opportunity to fine-tune things—like adjusting the developer-to-water ratio, as I did here, along with modifying development times. It’s all part of dialing in the process.

For this setup, I began by calibrating the lens wide open at f/4.5, focusing on the lighthouse in the distance to achieve center-frame infinity. The lens’s distance scale read 20 meters. I then re-focused closer to the corner of the frame, targeting the palm tree trunk on the right—the scale now read 4 meters. To calculate the hyperfocal limit factor, I noted the distance from 4 meters to 20 meters = 16 meters and divided by 2, arriving at 8 meters. With that, I removed the ground glass, loaded the film, closed the camera, and set the lens to 8 meters on the distance scale, aligning it with f/22 on the aperture scale—ready to shoot at the calculated hyperfocal setting.

Note: I did not physically reset the focusing ring’s infinity position; I just noted where to place it for hyperfocal distance shooting (I will use a very small screwdriver in the studio to do that later).

As you can see in image #1 above, I achieved a nice balance between close focus (the palm tree trunk) and distant focus (the lighthouse). After capturing two frames, I moved across the way to a different location.

Image #2 was more challenging—and that is precisely why I need to test and calibrate this lens for hyperfocal distance shooting rather than relying on ground glass alone. In this spot, there’s quite literally nowhere to go. To my right are bushes where alligators are likely resting. I checked the area as I walked down from the road—they’re usually sleeping at that time of day—but still, they won’t bother you if you don’t bother them. Just don’t bring a child or a pet!

I was standing on a very small patch of wet ground with the sun in my face, so I had to work quickly. I used the same hyperfocal distance setting as in Image #1, and all things considered—especially the strong wind that day (look at the ripples in the water)—I think the result looks good.

This first roll, tested during on-location calibration, turned out quite well. That said, I’d still like to fine-tune things a bit further—this time in the studio, screwdriver in hand, to make precise adjustments to the focus distance ring. Next, I’ll repeat the calibration test by shooting out the front door from inside my home—controlled, familiar, and just a few steps from the coffee pot.

Second Lens Calibration Test for Fotoman 6×17

For the second calibration, I relied more on my eyesight than on math. I began by performing a center-frame infinity focus at f/4.5 and recorded the distance from the lens’s metric scale. Then, stopping down to f/22, I rechecked focus using my 12x Schneider loupe—first at the center, then toward the corners (which were quite dark). I gently adjusted the focus ring in both directions until I could clearly see sharp detail from the center focus out to about 4 meters in front of the lens. That’s the point where I decided to recalibrate infinity. Afterward, I tested the hyperfocal setting at f/22. The results are shown below.

The image above shows my camera setup in the foyer of my home, pointed toward the neighborhood beyond. My trusty assistant, Joey, made sure the tripod was fully extended and secure. (By the way, Joey is three-legged—just like the tripod—so don’t worry, there’s no AI voodoo at play in his portrait!)

I was aiming for optimal sharpness using hyperfocal focusing at f/22, and I’m happy to say the results were right on target. This second round of testing was nearly identical to the first set I did out at St. Marks, which was encouraging. For this test, the camera was set up as I might shoot it “on the fly”—equipped with a Hoya “Orange G” filter (an older model, not quite a #21 but close), a budget-friendly lens hood, and loaded with black-and-white film.

Why this setup? Because conditions aren’t always ideal in the places where I tend to shoot. There are often plenty of obstacles, and setting up slowly isn’t always an option. So, when I run tests, I make them as close to real-world worst-case scenarios as possible. That means using gear I’d actually take into the field—affordable, replaceable components like this filter and hood. Thankfully, the hood didn’t intrude into the frame. Small victories!

Next up, we’ll take a closer look at the image and its strong depth of focus.

Above are 100% enlarged sections of the image. Would it be more appealing if it were a sweeping, beautiful landscape? Maybe—but not for what I’m testing. I want to see how the setup performs under ordinary, even mundane, conditions. Gorgeous scenes can be so visually rewarding and romantic that they sometimes distract me from spotting technical issues—if you know what I mean. Even quick digital camera scans of negatives can be pushed in post-processing to look better than they really are. But that’s not the goal here. This is about showing everything—warts and all. From the deep shadows along the inside walls to the soft, slightly blurry lines of the storm glass door (yes, I shot through it intentionally).

As best I can tell, focus starts around the porch step railing on the left, which measures approximately 2.486 meters away, thanks to my BOSCH Blaze Laser Measure. The tree limb near the top of the image? That’s from a street behind mine—so, a decent distance out.

I wasn’t thrilled with how Kentmere 100 film responded in these tests. I only use Kentmere for testing since it’s affordable compared to my regular 120 film stocks: Fujifilm Acros II, which is excellent for pinhole thanks to its near-zero reciprocity failure, and Kodak TMAX 100. My preference leans toward the finest grain I can get. For this roll, I did something a bit different during development: I used the AGO Rotary Processor with 510 Pyro. Usually, I process 510 Pyro with semi-stand development, so this was a bit of an experiment.

After digging around for what might’ve gone wrong with my development, I came across a post suggesting that using too much 510 Pyro developer can lead to grain clumping—which might be what happened. The AGO uses less chemistry than my usual setup (350ml vs. 500ml for 120 in a small tank), so I need to adjust my mix accordingly. Either that or I can mix my usual batch and pour off the extra before I start.

Also worth noting: I recently had to implement image and graphic compression on this site to improve speed, so you may notice a few minor changes in how things display.

Overall, I’m happy with the results, and later this week, I’ll be heading out to photograph with the Fotoman and my film of choice.

In Closing

Calibrating lenses for a camera like the Fotoman 6×17 is never a one-and-done process—it’s a hands-on exploration that evolves with every new environment, subject, and roll of film. With the Nikkor SW 90mm f/4.5 now fully integrated into the lens cone and calibrated for hyperfocal use, I feel confident heading into the field. This two-part process was a worthwhile deep dive into both technical precision and real-world usability. Whether in the wilds of St. Marks or the quiet setup of my foyer, the results have reinforced the importance of deliberate testing. I’m excited to see what this lens can do on my next shoot with my chosen film stock. Stay tuned—images from that outing will be added to this post soon.