February 2024 | How To

How not to attempt the repair of a vintage Auto Revuenon 55mm f1.4 lens

Auto Revuenon 55mm f1.4 attached to my X-E3

A while ago, I got bitten by the vintage lens bug. I had my Auto Revuenon 50mm f1.7 lens for a long time. I think the late 1970s, and I enjoy this lens immensely. It is how it renders colors, how the object in focus “pops.” It has its own character. Having a mirrorless camera makes using these old lenses so easy. I got curious and eventually found images made with all kinds of vintage glass. Yes, modern lenses are better corrected, sharper, and who knows what, but they are not always exciting.

I read great things about the legendary Tomioka lenses. The f1.2 version was too expensive, so I looked for f1.4 specimens. After a not-too-long search, I found a very nice copy, ordered it, and it came all the way from Poland to my doorstep.

I took the Auto Revuenon 55mm for a spin, and all was working well. It was like, hey bud, where have you been? It’s not something that happens with every lens. After a short while, however, the aperture stopped working. It stayed wide open. That was a bit frustrating. Naturally, I wanted to see why this was happening, so I watched videos on how to do things and which tools to use. I ordered a lens spanner, which I did not need. “Vacuum pads camera parts opener” – no idea where the vacuum comes into place – there is no vacuum generated by any stretch of the meaning, which I did use. And some other things that are useful for lens repair.

And the story begins – taking things apart

The first thing I did while waiting for the tools to arrive was fiddling with the cover ring. It came off simply by unscrewing it, no problem. No tools are needed.

After a few days, I fuzzed around with the focus ring, which also came right off. Not a problem yet, either. Also, no tools are needed. I saw a brass ring with four small screws in it. I unscrewed those as well. Now we start having problems. I’d recommend to leave those alone unless it becomes necessary to take them out. They are needed for the focusing ring, and since they are tiny, they are hard to get back into their slots. Live and learn. At least I kept the screws. Finding replacements could be problematic.

Finally, I did the one thing I probably should not have done, at least not without proper preparation. I unscrewed the helicoid. Getting everything out of the way, so to speak, I could see the mechanism that moves the aperture blades. At least something.

Aperture mechanism
Figure 1: You see the mechanism that moves the blades via the aperture ring, the spring, and the pin that connects this to the aperture.

Putting things together – The frustration begins

This was the start of a rather frustrating time. At first I could not figure out how to get things back together. I figured it will be easier when I take the lens groups out. For this I needed the rubber vacuum pads. Those are great. The two lens parts came out easy, and went back in just as easy. I did not take the actual lenses apart. With the lenses out of the way I could see the aperture blades and clean them.

Lens parts
Figure 2: The main parts of the lens:
top left – focusing ring, top right – bottom part with helicoid assembled,
bottom left – front plate, bottom middle – back lens, bottom right – front lens

As can be seen in figure 1, there are two pieces, they look like brass, on each side of the bottom part. Those need to go into the corresponding slots of the inner helicoid barrel. The thin metal pin will connect to the aperture.

Just getting the two helicoid parts together seemed more problematic than it was. At some point it clicked, in my head, not the lens. I realized that the two need to be connected counter clockwise. Now, screwing them together was easy.

Putting the helicoid back into the bottom part of the lens (first picture) was a lot of trial and error. The way that worked best for me was to screw the two helicoid parts together. Then attach the brass ring to the bottom part and screw it in quite a bit. Now I aligned it with the metal pin and screwed the inner helicoid until I could align everything. A bit of back and forward wiggling so the pin could go through the small opening for the aperture blades just enough to catch, then I screwed the brass part further in. This was not straightforward; there was a lot of back and forth. I was then testing the focus. It’s still way off. Infinity was at about five meters. Unscrew and repeat. Over time, the process became more straightforward, but the alignment was still off. I now know how to get the helicoid back together to assemble everything. Properly aligned focus is another story.

Look inside the lens
Figure 3: The lens partly put back together. The two helicoid parts are connected, the pin that controls the blades is in place, and the screws for the focusing ring are back in the outer helicoid (brass ring here in this photo). The big opening will hold the front lens.

Some kind of Semi Victory

The lens is back in one piece and focuses correctly at shorter distances. After about one meter, it starts to front focus based on the distance markers on the focusing ring. I haven’t yet managed to get things right.

After some more testing, I found that the lens focuses from a close distance to infinity. The airplane in the photo gallery below was the only object far enough away to be usable as an infinity test. To my surprise, the aircraft is sharp (the image might be sized up in the lightbox and appear a bit blurry).

This has been a rather lengthy journey, and I will take a break. The lens can focus from close to distant objects. I can use it for all kinds of photographs; I just cannot pay any attention to the focusing ring. For now, this will be good enough. 

Almost done
Figure 4: Together again, at last. This is the assembled lens without the outer focusing and front ring. One of the four small screws that is needed for focusing is visible in the fron center of the lens.

The slippery slope

After things were working again and the lens was completely assembled, I noticed that the focus ring started to slip. I might have tightened those little screws a bit too much, or maybe the metal inside the focus ring was a bit worn out. I loosened the screws a bit, not much, and that seemed to have done the trick. They now touch the focusing ring at a slightly different position.

I also found that it is important that the front plate has enough room and doesn’t touch the four screws when screwed in all the way at the infinity position of the lens. Touching the screws will interfere with focussing the lens, on top of the other issues.

What happened to the aperture blades?

At first, I thought/feared that maybe the spring was worn out. This is an older lens, and those things happen. However, this was not the case here. I can think of two options.

  • The blades had been a bit oily and not moving easily; they looked rather clean, though, or
  • the pin slipped out of its slot at one point, which would be odd, but I do not have experience with this kind of thing

Maybe the blades got a bit stuck. I did clean them with alcohol. I do not have lighter fluid and did not want to deal with it yet. Regardless of the cause of the problem, it is working well now.

Update: The aperture blades got stuck again. It looked like the pin could not move the small mechanism that moves the blades. I cleaned the blades again and carefully moved the pin until it was free. The aperture is working again, but I guess this will happen again.

Final thoughts

Despite the frustration and the not-so-stellar result, it was a great experience. I learned a lot about lenses in general and repairing them, what to do, and where better to keep my fingers off.

Instead of just taking things apart willy-nilly without caring about how to put everything back together, I should have taken notes and documented each step with photos, as described in this article. Oh well.

I was contemplating getting another copy of the lens during this endeavor. Still, all the lenses I found then were at least double the price, some in somewhat questionable condition. I still might get another working copy if I can find one for a decent price or a defective one to see how the helicoid is put together when the focus does work as it should. I haven’t found a suitable specimen yet. However, I found an Auto Sears 55mm f1.4 in very good condition for a reasonable price. I will make a comparison between the two Tomioka lenses as time allows.

The lens photos have been taken with my iPhone 15 Pro Max.

Images made with the Auto Revuenon 55mm f1.4 (Tamioka)

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