Modify your Canon FD aperture

F

funkbomb

Active member
I was disassembling a few lenses of mine for cleaning and figured a simple solution to modifying the aperture ring to work without the pushbearings that make the aperture click at the set intervals.

Perhaps a video tutorial for anyone who is interested:
http://www.frozenphoenixproductions.com/misc/slrlensmod_aperture.mov

As noted in the video this may work on other model SLRs as the construction does vary but not by too much, and the principal remains the same regardless.
 
this is awesome.
I have a lens that I dropped and shattered the inside on to practice with also:)

Q: Does this mean my canon lenses which won't change aperture at all when mounted to my letus will now be able to change aperture? Or does this only work on the ones that will already turn?

Thanks :beer:
 
Jack Daniel Stanley said:
this is awesome.
I have a lens that I dropped and shattered the inside on to practice with also:)

Q: Does this mean my canon lenses which won't change aperture at all when mounted to my letus will now be able to change aperture? Or does this only work on the ones that will already turn?

Thanks :beer:
Click to expand...
Have you tried the "Q-tip" trick?

Placing a cut-off piece of Q-tip to jam the metal lever in the correct position allows the aperture to be functional when mounted to a camera/adapter.

See here for example; http://www.redrockmicro.com/forum/viewtopic.php?t=3285&sid=c3f938c3e584f97dd65b9d80cb56cbbb

If that fails there is a way to fix those lenses, that I might be able to guide you through. But let me know if the Q-tip works.
 
funkbomb said:
I was disassembling a few lenses of mine for cleaning and figured a simple solution to modifying the aperture ring to work without the pushbearings that make the aperture click at the set intervals.

Perhaps a video tutorial for anyone who is interested:
http://www.frozenphoenixproductions.com/misc/slrlensmod_aperture.mov

As noted in the video this may work on other model SLRs as the construction does vary but not by too much, and the principal remains the same regardless.
Click to expand...

Nice video much nicer than reading article


Regards

Don
 
I had this pic of the "Q-tip" trick in action and thought I might as well post it:

Fstop_engBig.jpg


I cut a small piece of brass to hold the lever over (instead of a Q-tip). I've been using all of my FD lenses this way for 7 months or so and it works like a champ. A little more about it here.

Carry on.

Thanks for the video funkbomb.
 
Just out of curiousity--what lenses are you guys using that need the lever manually jammed? all of mine allow the lever to simply be clicked into position.
 
actually you don't need to use the piece of wood to jam the lever. Just push it hard enough and the lever will stick into place. My FD 50mm needs no stick.
 
funkbomb said:
Just out of curiousity--what lenses are you guys using that need the lever manually jammed? all of mine allow the lever to simply be clicked into position.
Click to expand...

Mine are all canon FD lenses: 28mm, 35mm, 50mm, 100mm.

DavidChia said:
actually you don't need to use the piece of wood to jam the lever. Just push it hard enough and the lever will stick into place. My FD 50mm needs no stick.
Click to expand...

None of the FD's that I have will do this. :huh:
 
there are two kinds ... one if you put on the back lens cap and turn it the iris will open and close, and another kind that won't unless its on a camera that's designed to flip the switch. So one will turn on any FD mount like the back lens cap or you letus and one only turns on a specific kind of Canon FD camera.

Timur can explain it with real words I think.

I'm probably getting it wrong anyway.
 
when canon introduced the FDsystem, it was beacuse they had "invented" the first fully automatic shutter and iris camera. the user only had to focus.

Back in the day, when lenses were fully manual, you had to upen up your apeture, look, focus, then meter, and close teh iris until the meter said the exposure was right, then you took the picture. this took a while. and plus the image after you stopped down got really grainy and dark through the viewfinder. so if something changed it was harder to see.

Canon said, since the metering/iris is instantly accesible in realtime because of their design, they descided to make the lenses run "wide open" all the time, unti lthe shutter was pressed. thsi way your view and focus was spot on.

what this means for us is, they had to make a whole bunch of engineering so that this mechanism could now be camera controlled. this means that the FD lenses have to be activated internally. not externally.

in the camera itself, it is of course possible to do it manually, but with the 35 adapters, they have no controll over the lens mechanism. sooooooooo....

there are 2 kinds of FD lenses. 1 kind that has a switch that will give a live preview ofthe Fstop, and the kind that cant. so the ones you can, are good for 35 adapter. the ones you cant.... not so much.
 
Thanks for the info Timur.

For those not able to fully load the movie in their browser, try right-clicking and saving to the desktop.
 
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