Collecting Cameras

Repairing the focus stop on a Certo Super Sport Dolly

Even though I’m not a fan of repairing my old cameras when they’re not working right, for an especially interesting camera I will do simple repairs that require tools I already own.

Certo Super Sport DollyLast year my friend Alice’s dad sent me all of his old cameras. He just loaded them all into a giant padded box and FedExed them to me. I’ve reviewed a couple of them here already. One I was especially excited to recieve was a Certo Super Sport Dolly, Model A, a 1930s folding camera for 120 film. Fellow photoblogger Mike Connealy owns more than one and makes wonderful black-and-whites with them. Its 75mm f/2.9 Meyer-Gorlitz Trioplan lens, set in a Compur shutter that fires as fast as 1/250 sec., is pretty capable.

I could see that this Super Sport Dolly showed wear consistent with heavy use, but the shutter sounded surprisingly snappy and a cursory check of the bellows revealed no light leaks. Those are the big things that can go wrong with cameras like this. So I loaded some Kodak Ektar and went out to shoot.

And then I turned the lens’s outer element to focus the camera — and realized that nothing stopped it from turning. It should turn no more than one revolution. I ended up accidentally unscrewing it from the camera. D’oh!

So I emailed Mike to see if he had any advice for me. He had better than advice: he accurately guessed what the problem was and told me he’d be happy to send me a part from his stash of spares to fix it. Thanks Mike!

It turns out that a ring in the lens assembly includes a stop tab, and that the lens’s outer element includes a pip that stops against that tab. I saw a pip, but no tab. Following Mike’s instructions I removed the front two lens elements to discover a broken ring inside. (In this photo, no part of the lens glass is touching the table!)

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Mike sent me a good ring. It’s on the left. On the right, well, you know. How in hades does a part like this break?

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I didn’t think to photograph the disassembly, but I did photograph the reassembly. Here’s the camera with both front elements and the stop ring removed. Note the white pointer just south of 3 o’clock on the camera’s face. It’s just a sticker. It is almost certainly a makeshift focusing reference point added after that ring broke.

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The stop ring simply sits in this hole, held in place by the inner element. I used a dinner knife to tighten the element. Its blunt blade was the right thickness and was long enough. But you can see I marked up the slots a little bit getting it screwed in.

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Then I used my fingers to screw in the outer element. Now, you can’t just screw in the element any old way, and have the stop pip and tab any old place, and expect the camera to focus accurately. Really, you have to collimate the lens. This involves placing a ground glass in the film plane, pointing the camera at something far away, and twisting the lens until the ground glass shows everything at infinity is sharp. That sounded like a lot of hassle. And besides, that roll of Ektar was still in the camera! I hated to waste it.

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Fortunately, Mike gave me a quick and dirty way to set the lens set well enough. He said that the outer element would screw in at three different starting points. I could use any of them I wanted, but since I had to tighten the inner element against the stop tab ring first, he recommended using the thread point that placed the stop pip near 12 o’clock. His experience was backing the stop pip off a hair gave accurate enough infinity focus.

So I screwed in the outer element until I got it in that positon, and saw that the stop pip wound up just a hair shy of 12 o’clock. So then I unscrewed the outer element, loosened the inner element, and moved the stop ring to a hair off that pip’s final position. Then I had to unscrew and rescrew that outer element repeatedly until that pip wound up at near 12 o’clock again.

About that stop pip. You see it in the photo above at about 8 o’clock. You have to remove it from the outer element, screw the outer element in most of the way, and then screw the pip back in. Otherwise, the pip blocks you from screwing in the outer element all the way.

This pip is an itty bitty bit of metal. Fortunately, it is slotted on the end. My ittiest-bittiest jeweler’s screwdriver just fit that slot. Unfortunately, that screwdriver isn’t magnetized, so it was guts and glory screwing that pip out and in without losing it. My entire catalog of four-letter words was poised and ready should challenges with this step have made them necessary. Fortunately the pip came out and went in with only a little drama, reserving my words for another more frustrating day.

One reason, but certainly not the only one, that I don’t do more camera repair is that I really don’t like hearing those four-letter words come out of my mouth.

I took the Super Sport Dolly to Crown Hill Cemetery on a chilly late-autumn day to finish the roll of film. I shot at stuff near and far and then sent the roll off for processing and scanning. I don’t want to throw the processor under the bus so I won’t name it, but they kind of botched the scans. They apologized deeply and told me to send the negatives right back to them for rescanning. And then their medium-format scanner broke. That was two weeks before Christmas. The lab owner told me a harrowing tale of scanner repair and re-repair, but promises that the scans are finally in the mail.

But here’s one photo from the original scans that turned out well enough to show that focus is pretty good at infinity. The faraway details are a little soft, but that could be part of the scans’ many problems. Click it to see it at full scan size.

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It also shows a slight light leak. See it there, on the right, about 4/5 of the way down? It’s faint in this shot but more pronounced in others. So now I get to try to find that leak. I’m betting it’s in the bellows. Mike tells me a bright flashlight in a dark room should find it, and a dab of black fabric paint should fix it right up. That job should be easy enough not to need any four-letter words.

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11 thoughts on “Repairing the focus stop on a Certo Super Sport Dolly

  1. Excellent work! And a nice camera it is as well, and well worth the hassle I would say. The negative scan looks brilliant as well, and that tiny light leak should be easy enough to get rid of at some point.
    Crossing my fingers, looking forward to next batch of scans.

    Like

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