Canon FD S.S.C 200mm f2.8 loose aperture?

Martinorsy · Joined: 07 May 2018 Posts: 11

Hello!

I have recently bought this beautiful lens, the glass is in excellent shape but there is something wrong with the aperture ring and im trying to figure out how to repair it, or at least find out what is wrong with it.

The problem is that the ring used to changing the aperture of the lens is kinda loose, there is no clicking sound/feedback, that is strange. And also when I set it to open aperture (2. Cool

it slowly starts to close again. Also when I open the aperture, I can see that the aperture is not open completely and cannot be forced to open more.

Please, could you folks tell me what you think might be wrong with it or whether is there any way of repairing it?

I have recorded the issue here for better illustration: https://youtu.be/0XC0_gBYF4c

If needed I can provide more info, take a picture of something etc.

Thank you very much for any kind of feedback/help!

DigiChromeEd · Joined: 29 Dec 2009 Posts: 3462 Location: Northern Ireland

Do you have the same problem when you remove the Fotga FD-NEX adapter?

Martinorsy · Joined: 07 May 2018 Posts: 11

Well, when I remove the adapter the aperture ring is still loose. I think the problem may be somewhere inside.

Martinorsy · Joined: 07 May 2018 Posts: 11

I thought, mayble it is possible that the previous owner tried to remove the ball bearings inside in order to make the aperture control smooth instead of default "clicking" and somehow screwed up putting everything back in proper order when assembling the lens?

I dont know, thats just a thought that crossed my mind.

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

Yep. Probably incorrect reassembly. Or may be one of the internal mount springs has snapped.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

I'm inclined to agree with Gardener. If the aperture ring doesn't click, then the ball that sits in a small hole under the aperture ring with a spring in it to apply pressure to the ball is most likely missing. It is very easy to lose this ball. Good luck finding a replacement. Although I seem to recall there being mentioned a business that can supply these small ball bearings. Micromark maybe?

As for the looseness of the lever, yeah, I'm willing to bet that a spring has come off or has broken. Much more likely it just came off and the previous owner didn't bother trying to reconnect it.

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

Some of the Canon lenses use bearing rollers for detent, but one can be replaced with a ball if it has gone missing.

Martinorsy · Joined: 07 May 2018 Posts: 11

Thank you very much for your replies and useful info! I'll probably have to go to some service cause I don't wanna go too deep into the lens on my own trying to repair it, especially the spring.

papasito · Joined: 09 Jan 2015 Posts: 1658

Anyways. can you tell us what kind of IQ did you see in the images taken with that lens.

Is as good as someone says?

Good CA rendering?

Contrast?

Resolution?

Martinorsy · Joined: 07 May 2018 Posts: 11

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

Martinorsy · Joined: 07 May 2018 Posts: 11

Martinorsy · Joined: 07 May 2018 Posts: 11

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

I can not really see what's going on all that well, but on the second video - check that the silver adjustment ring that you trying to budge with a screwdriver did not slip past the cam that sets the aperture value.

Martinorsy · Joined: 07 May 2018 Posts: 11

Gardener · Joined: 22 Sep 2013 Posts: 950 Location: USA

So what most likely happened is the person who declicked it was not experienced with breech lock mount and accidentally moved the ring too far clockwise when trying to wiggle the mount into its place.

Martinorsy · Joined: 07 May 2018 Posts: 11

Okay, so I have found out why the aperture couldn't open completely wide open! (as i have described in the post and shown in the very first video).

I will write everything here, in case somebody else will have the similar problem and will search for some solution.

This part is not original! It is different,

It should look exactly like this:

This means that the previous owner for some reason replaced this. I have even noticed that it is glued and there is only one screw holding it in place, the second screw doesnt even fit there.

So the original part is kinda longer to the left side, but the replaced one is not. So what happens is when I turn the aperture ring to open the aperture completely (in this picure)

it cannot be opened to the maximum because of the shorter unoriginal part which is responsible for moving the aperture.

I just have to get the original part somewhere or make it longer to the left on my own somehow, that's all!

The remaining problem is that when I open the aperture, it slowly starts to close on it's own (shown in the very first video).
I think that it can be fixed by inserting the missing ball bearings! I'll just have to get/buy them somewhere Very Happy

I could probably look for some old FD lenses for parts to fix these 2 problems with this lens.

I'm sorry if I described something strangely, especially in this reply, I'm not a native english speaker, I'm from Czech republic (Central Europe).

Thank you very much for helping me out with this, especially you Gardener, I wouldn't figure this out on my own. Your replies helped me alot and in addition to that I have gotten to know this lens more and how it works, it really was interesting.