Canon FT QL shutter

[hartacus]

Hi all,

The second shutter curtain on my Canon FT QL sometimes doesn't close fully, resulting in a light band down the side of a frame. It's intermittent (maybe one frame in 6), and it seems to happen only at 1/125s strangely enough.

I've read about shutter bounce causing similar symptoms, but I'm suspicious that it might be not closing rather than closing too much and bouncing, if you follow me. Can something like capping occur just on the second shutter? I understand capping is when the second shutter catches up with the first, but I'm wondering if the second could also give up the chase early. And if so, whether the fix might be to tighten the second shutter spring (something which, unless I'm mistaken, would worsen the issue if it is actually bouncing). Any advice would be great!

 

[John Koehrer]

Is the light band on the negative or print?
If the shutter isn't closing fully you should have a dark band on the negative.
If you open the back and watch the left edge of the film gate, it's sometimes
possible to see it fail.

you can see bounce too but it may be harder to see. If I remember right the FT series used
a leather brake pad just like a car with drum brakes. over time, the leather compresses or can even fall off.

 

[summicron1]

the second curtain most certainly can hang up -- whether it is capping or bouncing, it is time for a clean and lube, change the oil, rotate the tires. 40-year old cameras need that sort of thing.

 

[benjiboy]

Your camera must be nearly fifty years old and needs professional servicing.

 

[hartacus]

Is the light band on the negative or print?
If the shutter isn't closing fully you should have a dark band on the negative.
If you open the back and watch the left edge of the film gate, it's sometimes
possible to see it fail.

you can see bounce too but it may be harder to see. If I remember right the FT series used
a leather brake pad just like a car with drum brakes. over time, the leather compresses or can even fall off.

I checked the negs and prints: dark band on the negs, corresponding light band on the prints. Some examples attached.

I've tried watching the shutter - i haven't been able to notice it bounce, but i'm honestly not sure if that's because it's not bouncing or because it's moving too fast. If I had to say, I'd say it doesn't look like it's closing fully. But it never leaves a gap, it just doesn't overlap the first curtain as much as it should.

Interesting point you made on my other post linking this with the mirror issue - I'd never thought of that. I'm not sure they're entirely related, because they don't seem to correspond exactly - one frame i know was shot with a blacked-out viewfinder doesn't have a frame with a light bar on either side of it. However, another of the light bar frames is followed by a very under-exposed frame, possibly indicating I wasn't trying to expose it properly. So, maybe? Assuming the shutter was being caught up by the mirror return mechanism, would that account for the slight angle of the light bar in that first picture? (That is, is the mirror catch near the top left of the frame, looking from behind the camera?)

A service is certainly on the cards. Aside from this issue, the 1/8s and 1s shutter speeds don't work - I even found a repair receipt from 1984 where the repairman told my dad he couldn't fix that issue (gave him a discount, thankfully). Mostly asking here from a combination of economics and curiosity; this is the camera I'm most hesitant to work on because of its sentimental value, but I have other cameras I feel more comfortable tinkering with, and I'm curious to know what the solution would be even if I'm not brave enough to implement it!

 

[hartacus]

I even found a repair receipt from 1984 where the repairman told my dad he couldn't fix that issue (gave him a discount, thankfully).

Haha I just looked at the invoice from 1984 again. It reads: "Have reduced price because slow speed train needs replacing & circle on prism came off when clean. These parts are not available."

I've often though it was strange to have a match needle with nothing to match to

 

[flavio81]

Sounds like a case of BAD REPAIRMAN...

Looking at your pictures, it looks as the classical problem of the second curtain bouncing or not moving freely when closing. If the 1/8 speed also had problem then most likely it's just a lubrication issue on the whole of the camera.

Don't touch the shutter spring adjustment. Try dripping a bit of lighter fluid (Zippo, Ronsonol, etc) on the part of the bottom of the camera where the main spindles are, and cycle the shutter many times to see if the problem gets solved.

You can usually detect shutter bounce with your eye, just choose a high speed and look through the curtain in a darkened room, the camera facing to a bright wall.