Canon F-1 / FD 55mm f1.2 problem

Jeremy Greenaway · Dec 19, 2019

Was going to give my minty Canon F1 New an airing - but problem: the likewise minty very early model FD 55mm f1.2 lens (a belter) refuses to be separated from camera body.
Am I missing something?
This is the version with a silver collar for the breech lock and does not have the detent release button of later FDs. Likewise, there is no release button on the body.
I've tried with all my might (within reason) to unlock the lens - press down hard on body and rotate anticlockwise to line up the two red dots. But it won't budge.
Haven't used it for a while, am I missing something?

Kino · Dec 19, 2019

You are just trying to rotate the ring, right?

It is a breech lock lens; the lens barrel doesn't rotate like a bayonet mount.

Not trying to be insulting, just wondering if this somehow was forgotten...

MattKing · Dec 19, 2019

Are you sure you are rotating the ring in the right direction?

Kino · Dec 19, 2019

Inquiring minds want to know if you got it!

If that doesn't get it, you might have to put a drop or two of alcohol around the ring to break it free...

AgX · Dec 19, 2019

I once acquired an AE-1 with mounted newFD 50mm which by no means could get unmounted. I had to disassemble the mount at the lens. (Actually quite easy, getting the mount together again was the problem...)
The reason the mount was stuck, was a tiny grain of sand in the bayounet. Actually I found grains of sand everywhere, in the exposure correction button, inside bottom cap etc. The camera must have been at the beach.

I never ever experienced a stuck breech-lock mount though. But my bet is also a grain of sand. In contrast to the newFD mount the breech-lock mount is not to disassamble that it falls apart in parts.
Likely the only way is sheer force. However, both, the breech lock ring and the male bayonet are standard parts and can substituted from cheap lenses or bodies (for the latter and the newF1 I assume so).

AgX · Dec 19, 2019

Instead of sheer force you may try a heat-gun just on the breech-lock ring. Cover the lens and body with aluminium foil to yield some thermic insulation for that moment.

Ariston · Dec 19, 2019

AgX said:
Instead of sheer force you may try a heat-gun just on the breech-lock ring. Cover the lens and body with aluminium foil to yield some thermic insulation for that moment.

Or use a blow torch, like the car mechanics!

AgX · Dec 19, 2019

No need to ham up....

There might be a tiny expansion sufficient to free that thing.

As further alternative you might consider boiling water applied by cotton bud.

Johnkpap · Dec 19, 2019

The first thing I would try is lighter fluid, I have been amazed st what this stuff can free up

Johnkpap

AgX · Dec 19, 2019

I never ever came came across a Canon or even clone FD breech-lock that was sticky in unmounted state. The worst samples were slow at auto-closing that ring, but not unresponsive.
A ring really stuck by hardened lubricant seems thus very unlikely to me.

AgX · Dec 19, 2019

The very last resort would be circular cutting off that part of the ring that grips behind the male bayonet. This would be a bit tricky as the mount for the prism is protruding, but it should be doable.

Kino · Dec 19, 2019

The suspense is killing me...

I hope he didn't have some fatal lens-removal accident.

blockend · Dec 20, 2019

If the focus and aperture scale are properly centred, it sounds as if something has come adrift in the breech mechanism. There are stories of FD lenses being mounted incorrectly, but I've yet to experience the problem in breech or bayonet variants. FD lenses have two short and one long tang, so only go on one way, though no doubt people have found a way!

AgX · Dec 20, 2019

The breech-lock is of the most basic kind mechanical-wise, just a simple thread. Think of the cap of a beverage bottle...

blockend · Dec 20, 2019

AgX said:
The breech-lock is of the most basic kind mechanical-wise, just a simple thread. Think of the cap of a beverage bottle...

Yes, but the mount has to be lined up. Difficult to do one-handed, which is probably why Canon changed to the new FD.

AgX · Dec 20, 2019

Yes, lining up and getting the breech to lock can be tricky if uninitiated and acting hastily. But hardly if one knows how to do it.
If the breech-lock lens has the auto auto-lock feature it sure helps if the its thread and the respective aperture mechanism is lubricated freshly.
However you cannot mess-up that mount.

A different thing is the newFD mount, if you by purpose(!) try to mount the lens just so much that its mount gets unlocked to then open its aperture completely for checking. As when being at a store with no other unlocking tools at hand. Don't do so!

Jeremy Greenaway · Dec 20, 2019

Thanks for all the responses and advice. I'm not exactly a newbie at photography - been a practitioner for 65 years using everything from VN and Speed Graphic 5x4, Rollei, Blads, Leica et al and the F-1n too. Never had a problem swopping lenses before - as well as the stuck 55mm f1.2 I have and use 200mm f2.8, 135mm f2.8, 85mm f1.8, 50mm f1.4, 35mm f2, 24mm f2.8, 20mm f2.8, but the last time it came out of the kit locker was four or five years ago. But thanks to your help it's now off - I'd forgotten the aperture ring had to be set to the green dot auto mark . . . problem solved, thanks all! (these damned senior moments)

AgX · Dec 20, 2019

Jeremy Greenaway said:
I'd forgotten the aperture ring had to be set to the green dot auto mark . . . problem solved, thanks all!

Not at all...
The switch (shutter-priority/manual aperture) cannot be the culprit. The respective actuator at the lens, which protrudes, engages in the respective hole at the camera mount.
Only at bodies, that do not have this hole, the protruding actuator would make mounting of the lens impossible, and must be retracted in advance. But that was not your problem at all.

Likely you just applied more force in twisting that breech-lock ring than yesterday.

Jeremy Greenaway · Dec 20, 2019

Not quite sure what you mean. This 55mm f1.2 lens is the first version of the FD and has a different mount from later models - there is a quite wide silver knurled locking ring without the detent (little knob) on later versions. It doesn't have an AE lock pin on the lens mount, and locates solely by lining up the red dots on lens and body. Setting the aperture ring to the green 'o' auto aperture setting is what locks it in place.

AgX · Dec 20, 2019

As I said the status of that switch does not interfere with mounting a lens, as long as the mount at the body has a respective hole, as your camera has.
And even without that hole one still can mount that lens by retracting that protruding pin in advance.

BUT your problem was not mounting that lens, but UN-mounting it. And here the position of that switch by no means interferes.

Whether an FD lens has a locking button for that switch or not, does not matter. A true FD lens always has that switch.

Jeremy Greenaway · Dec 20, 2019

I think we must be talking about different camera versions. Nothing like you describe.

Mainecoonmaniac · Dec 20, 2019

I'm assuming it's the old Canon FD system. If I remember correctly, there's a pin in the lens mount that locks the ring in place. For it to release the locking collar, the pin is depressed against the camera body. I think the collar locks to prevent the collar from rotating to help the mounting of the lens. Have you tried gently pressing the barrel of the lens against the camera body then trying to turn the locking breech mount collar. The newer generation have no collar and a release button towards the back of the lens. I wish you luck.

Jeremy Greenaway · Dec 20, 2019

As per my previous replies, yes, it's the 'old' FD type lens - very early s/n and more akin to an FL with, as I've said, no interlock like later versions. It's a simple rotating silver sleeve which can be attached/detached only when the green 'o' is set at the infinity position. When the aperture is being set manually, the lens is locked in place. It removes/locates quite easily but firmly without any undue pressure when the aperture ring is set in the right place.

Mainecoonmaniac · Dec 20, 2019

Jeremy Greenaway said:
As per my previous replies, yes, it's the 'old' FD type lens - very early s/n and more akin to an FL with, as I've said, no interlock like later versions. It's a simple rotating silver sleeve which can be attached/detached only when the green 'o' is set at the infinity position. When the aperture is being set manually, the lens is locked in place. It removes/locates quite easily but firmly without any undue pressure when the aperture ring is set in the right place.

Do you think it's the DOF preview on your camera?

AgX · Dec 20, 2019

Mainecoonmaniac said:
I'm assuming it's the old Canon FD system. If I remember correctly, there's a pin in the lens mount that locks the ring in place. For it to release the locking collar, the pin is depressed against the camera body.

There is no such pin.

As I said the mechanics are the same as the screw cap at a bottle.

Only at newFD there is a locking pin, at the barrel. But still this does not engage at the camera, but just is a lock within the lens itself, needed to avoid unlocking of the mount during handling of the barrel. As here the whole barrel controls mounting/unmounting and no longer that slim silver ring.

Canon F-1 / FD 55mm f1.2 problem

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