How To: Adjusting Shutter Speeds/Repairing Light Leaks on Canon FTb and FT QL Cameras

I like the Canon FT QL and FTb cameras, but many suffer from light leaks and shutter capping. The seals on the back are the usual culprits on the light leaks. If the back needs seals, this is easy to fix w/ some felt at the hinge joint on the side, and some crochet yarn laid into the channels of the body (untangle the yarn and use just one thread from the yarn). But on this FTb, the light leak was due to the shutter curtain being slack and not returning to it's seat. Sometimes it would work properly and disappear behind that edge where the pen is pointing, other times it would stop before going the full travel. I found the problem by shining a light into the mirror box and looking into the back of the open camera in a dark closet. The curtain travels from right to left, and is supposed to go inside the black metal edge of the film opening (shown in the photo below where the pen is pointing to). It wasn't returning all the way and the light was streaming in from that side.



There is a lot of erroneous information on how to cure shutter capping on the web, and I was snipe hunting for a long time before I found this fix: If you take the 3 small screws out of the bottom of the camera, the bottom plate comes right off. Inside, once you cock the shutter to uncover them, these two screws w/ the red arrows are the shutter adjustment screws. The screw w/ the yellow arrow is the one that needs to be loosened to adjust them. It is sealed w/ lacquer paint, but I chipped away at it w/ a tiny screwdriver and got it loose. It holds a small arm that fits into the gears of the two shutter adjusting nuts and keeps them from backing out when they're tensioned.



Once it was loose, I gave the adjusting screws a half turn or so, enough for the shutter curtain to go inside the film gate area where it was supposed to be, then gave them another 1/4 turn for good measure. Firing the shutter many times convinced me that the curtain was now reliably returning all the way beyond the film opening. You really need a slotted screwdriver w/ a prong like end to get around the shaft in the middle of the adjusting screws, but I simply pushed them around w/ a screwdriver by hooking it into the gears and pushing them around. Next, I snugged down the retaining screw in the middle, and gave everything that might move a little dab of acrylic paint to hold things in. After the adjustment, the shutter curtains were more taut (but not overly so) and the exposures were better on my next roll of film. I soaked everything in some lighter fluid to clean it up (it was really dirty before these pics), and gave the most likely places a small dab of light, synthetic bike chain oil.

This is about a 5 on a scale of 10 for difficulty, and most people w/ good eyes and some decent screwdrivers can do it. Spending some time puzzling it out before hand will be of assistance. Here's a neg from before the fix, and the second shot is how the whole roll came out after the fix.

Must check something first.

I have a collection of parts cameras with broken shutter springs.

I accept parts cameras in zip lock bags, I don't reveal my sources.

Momus,

I will try to walk you through this as clearly as is possible. If you do not have excellent close vision, get a magnifying glass.

The Canon ‘mechanicals’ (those SLRs with clockwork, not electronic, shutter timings) are very similar in this regard. Do this: remove the bottom plate of your Canon SLR: There are two screws on the face of the bottom plate plus one more screw on the plate’s end-side. Don’t lose these screws, Momus.

Now, hold the SLR with bottom facing you, vertically, so that the lens mounting area faces LEFT. About one inch from the far end of the bottom are two serrated wheels (screws), placed horizontally, with a screw in the center holding two tiny ‘levers’ which engage the serrated wheels so that they cannot turn. These two wheels are the tension springs for each curtain.To prevent capping at high speeds (1/500, 1/1000) you must increase certain curtain tensions. How to do this? But, first:

With many mechanical SLRs of different brands, like Minolta SRT and Pentax K1000, if you remove the levers that engage the serrated wheels, those wheels quickly unravel. With such cameras it thus becomes necessary to hold that wheel WHILE pushing the lever away from the serrated wheel in order to control that wheel’s movement. With the Canon mechanicals, this is not necessary. If the levers engaging the serrated wheels are loosened, those wheels stay put (at least temporarily). Now, a ‘step-by-step’ on how to do this.

On the Canon mechanicals, those wheels are somewhat hidden by various metal shafts, but can still be seen and accessed. First, loosen the center screw (by turning that screw CLOCKWISE) which holds the tiny levers between the two serrated wheels. Then, with a tiny screwdriver, push away the lever that is placed against that serrated wheel which is CLOSEST TO THE BACK OF THE SLR. Lever removed, that serrated wheel will not be prevented from being turned manually. Use the same tiny screwdriver to carefully insert into one of the sawteeth in that serrated wheel. NOW: slowly and carefully begin turning that serrated wheel about 180 degrees COUNTER CLOCKWISE. This slightly increases the proper spring tension in the relevant curtain.

That done, open the SLR’s back, cock the shutter, set shutter speed to 1/1000, have (lensless) SLR body facing a bright area (with the back of the SLR in subdued light), and while closely observing the film aperture in the back of the camera … FIRE. You should see either a full 24 X 36 ‘exposure’ or, at least, a decided improvement. If you need to turn that wheel a bit more (counter clockwise), try another 180 degrees. This should do it. I have yet to find an SLR that I cannot stop capping in this easy way.

Done? Good, Put everything back now. First, make certain that EACH lever is engaged with its respective serrated wheel. Then … tighten those levers by turning that center screw COUNTERCLOCKWISE. Then, clean off accumulated dust inside the bottom plate and body so dust will not stay in the SLR. Then put back the bottom plate (three screws, remember?) - David Lyga

It takes some familiarity, but this enables you to get many focal plane shutters reasonably close to correct. As Rick says once you know how to read the shape and size of the slit it will also inform you which curtain is faster than which and whether or not they are tapering across the gate. Would I like a proper shutter tester? Absolutely. But this is still a whole lot better than nothing.
http://rick_oleson.tripod.com/index-135.html

Also there are some cameras that won't respond ideally to compensation of spring tension. Early Pentaxes are a case in point. Unless they get some cleaning it may be impossible to get the high speeds consistent across the gate regardless of spring adjustment. No short cuts with some of those.

I find the Asahi H1a is easiest to fix using a similar way. Prehaps, Brett, you are talking about something even earlier. - David Lyga

David Lyga said:

I find the Asahi H1a is easiest to fix using a similar way. Prehaps, Brett, you are talking about something even earlier. - David Lyga

Click to expand...

Haven't looked at the H1a but SVs, Spotmatics etc. I agree with you re: procedure for getting speeds back on track. But the Pentaxes often have been recalcitrant for me without mechanisms being cleaned (tops and bottoms of spindles and gears etc). Last SV I looked at (last week) I was able to stop capping easily enough, but obtaining even slit width across gate defied all attempts, despite setting curtains from nil tension progressively several times. Suspect second curtain release needs adjustment or cleaning under top cover to get linearity of slit width across gate, so will have to investigate (too many projects on the go). I may have another look at it later this week. Beautifully made, and so smooth to wind though. I don't put a lot of stock in leaving most leaf shutter cameras uncocked when not in use, however with the early Pentaxes, given their uncommon propensity for losing spring tension, perhaps there's some merit in this. They seem much more prone to capping and tapering than, Eg. SRTs for instance. Last fp shutter I tackled was a TM Icarex which had been wrongly assembled with gear timing off when I got it. Working perfectly now and oh so nice to use, and with M42 bodies coming out my wazoo the Pentaxes aren't a pressing priority to sort but I would like to get there eventually.
Cheers,
Brett

Yes, dirt and grease can cause problems. Remember when I said to clean all dust in that area when the bottom cover is off? Wise advice. Dirt gets in after decades of that camera being everywhere.

The SV and H1a are identical as far as curtain adjustment is concerned; those particular predecessors of the Spotmatic are among the easiest SLRs to work with.

But I do love that picture of Momus's cat. - David Lyga

The first picture of the flower (if not a negative) looks like a light leak. It would be dark or black on one side to be a symptom of shutter capping.