Cant set the aperture on Canon FD lens

[asjoker@gmx.de]

I just got my Canon FD 50mm 1,8 lens from Ebay and i am kinda disapointed.
It has only 5 lamellas which is very poor even if i dont have any experience with that.

Anyway i got another problem with the aperture:

I cant set it. Well i know that there is a lever which has to be engaged for the aperture to function and i already put a piece of plastic inside there. You can see it here:

But the aperture still doesnt change if i turn around the Ring.

As i have no praxis-experience with lenses i am also surprised that you can turn the aperture ring while the lever is NOT engaged. That would mean, while turning the ring i would change all the settings. So i change it from 22 to lets say 1,8 (while the lever is not engaged) and the aperture is still on 22 which would mean i cant set it anymore even if the lever is engaged.

Considering that i tryed every possible aperture stop in case that it only works when its on the right one but nothing happened. Dont tell me its destroyed...

Please give me some advice...

 

[Huy Vu]

Stopping the lever alone isn't enough, you have to put it on a mount.

 

[asjoker@gmx.de]

Thx for the fast answer !!

Alright, now i have put on the cap of the back from the lens.
Well the aperture does react but than again there seem to be a problem.

I dont know what the Setting A means but i know that 1,8 must be wide open and 22 must be almost closed.

If i set it to A its wide Open.
If i set it to 22 its almost closed.
Everything between those two is also available, so if i set it right between A and 22 its half as open as possible.

Now we come to the weird part:

From 22 to one stop before 16 (not 11) the aperture is getting bigger and bigger. But everything above that spot (11 and a half) dosnt work. So the aperture is just as big as 11 and a half if i turn it to 1,8 or 2,8 or 5,6.

Whats wrong? ^^ Is it destroyed?

What i forgot to mention.
The biggest possible aperture size (in this case A) is just as big as in the picture.
Seems to be very small huh? ^^

 

[Wayne Kinney]

The lens must first be fully engaged into an FD mount before it will work.

 

[asjoker@gmx.de]

For now i dont have a FD camera.
But ialready put on the cap for the back of the lens which has the same form as an FD Mount.

And even if not - When the lens is not connected with an FD Mount the aperture should always be WIDE OPEN. But its not! Its just as big as shown in the picture above and thats as big as ... 11 or something like that.

Could be broken...

 

[Toenis]

Don't worry too much. If the lens were unscrewed from the camera in "A" position it will be locked till you get your proper FD mount.
I have forgot the lens into "A" mode many times when unscrewing from the F1 body and in some cases it even didn't mount on my Letus because of that. Mostly with 24mm f2 lens that is.

T

 

[asjoker@gmx.de]

Hmm i dont get it all what you said (cause of my bad english) but anyway i got it

With twoneils help

How its done for others: (Picture from Twoneil)

You need to put up something like plastic to the lever and than you can control the aperture with the aperture ring just like with every lens. It worked

Thx 4 the answers anyway

 

[teemue]

There's a better way..

Just take the cap that came along with the lens, cut (or sand) out the pins that are stopping it to screw all the way to the "click" point. Be careful - make it smooth, don't leave little pieces that might break and stay inside the lens when you click it in.

Now you can even use the cap in your own DIY adapter by making a hole to it and using it as a mount ring.

Someone correct me if this is not the way to set the aperature. At least it is a good way to make a cheap DIY mount.

 

[frobozz]

I'm not sure what questions still remain here, but as a longtime Canon FD still camera user, I'll state some facts about FD lenses and see if that helps anyone...

The "A" position on the lens is for use on Canon still cameras that have auto-exposure where the camera controls the aperture automatically (eg AE-1). In this mode, the lens needs to be wide open so that the camera can set the aperture using a lever on the back of the lens. So you should not look at the "A" position as being "even more stopped down than F/22" - it is simply a completely separate function. A function that is of no use at all on a 35mm adapter, where you are always manually controlling the aperture.

The "A" position is signaled to the camera by a little pin that juts out of the back of the mount... and if your 35mm adapter doesn't have a corresponding hole in the mount, you won't be able to mount the lens! Another reason to never have a lens in the A position when using it on a 35mm adapter. (In the same way, you will not be able to move the ring into the A position when the lens in mounted on a mount without the hole.)

As mentioned a few times above, the aperture mechanism doesn't function unless the lens is mounted. In the case of the new style (bayonet) FD mount, the rest position of the aperture is the half-stopped-down state pointed out above. It's overthinking things to worry about that, since you can't use the lens unless it's mounted anyway. Mount it, and the aperture will behave. (The older style FD lenses, with the silver breechlock ring do in fact default to wide open when unmounted.)

As you noted in the first post, you have to wedge something in the slot to keep the control lever moved to the side, in order for the aperture ring to control the aperture even when the lens is mounted. This is the "stop down lever" usually controlled by the still camera at the moment of exposure, or with the DOF preview button. Canon actually made a little official wedge piece but good luck finding one. Your solution above is fine. But here's an advantage of buying the older breechlock style lenses, if you have a chance: that lever has its own built in wedge! Simply move it counterclockwise until it meets resistance, then push a little harder and it will "click" into place. This is the "FL mode" of the lever, which allowed the then-new FD lenses to be used on the older FL-mount Canon cameras which had fully manual aperture control. Why they ditched that when they went to the newer style FD mount I have no idea... I guess because it had been a decade or more since they had sold any FL cameras?

Here are the two eras of FD mount... newer bayonet style on the left, older breechlock style on the right:

Here is the business end. The lever that needs to be wedged is at the top of the picture on both lenses. Notice how the older lens on the right has a much longer slot for the lever to move in:

And finally, here is the older lens with the lever clicked over into the "FL mode" position:

Except for a couple of examples (like the 14mm lens above), FD lenses were available in both mounts along the way, so for adapter use you should definitely try to hunt down the older version for ease of use.

Any other FD lens questions, just let me know!

Duncan