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Canon FD lenses aperture question

jdphoto

Well-known member
I've been using the Canon FD 85mm 1.2L on a New Canon F1 for film and also on my RP for digital. On the RP, I was able to see the effects of the aperture using exposure mode enabled, but now when turning the aperture on the lens when using either camera I don't see any changes in the size of the aperture or exposure. When using the DOF indicator on the F1 it does not stop down or move the blades. I know that to aid in focusing the F1 will keep the lens open and then stop down to selected aperture when pressing the shutter, but is there a way to look through the lens and observe the aperture changing when clicking different stops? Thanks for any input.
 
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jdphoto

Well-known member
Not sure what you mean by this. Are you pushing the stop-down control as described on p 63 of the instruction manual?

https://www.butkus.org/chinon/canon/canon_new_f-1/canon_new_f-1.htm
Yes, I did. Thanks for the link. Interestingly, it seems to work on the F1 now. I can look at DOF with switch (red line ) out and the blades move fine. However, with the digital RP, turning the aperture ring on the FD has no effect on the exposure preview even though the exposure enable is selected on the menu. More than likely it's something i'm doing as these FD lenses are built like tanks!
 

Oren Grad

Member
With the caveat that it's been a very long time since I last handled Canon FD gear, my recollection is that the original breech-lock FD lenses were indeed built like tanks, but the last-generation new-FD lenses that mimicked a bayonet had more complex and somewhat less robust mount construction.

Anyway, Mike Butkus has some FD lens manuals too:

https://www.butkus.org/chinon/canon/canon_fd_lenses/canon_fd_lenses.htm

A close read suggests that when not used on an FD body, the FD lenses need a mount adapter that locks the automatic aperture lever on the mount in the correct position to allow manual diaphragm control.
 

jdphoto

Well-known member
I think it might be the Novoflex adapter. When using the FD 85mm 1.2 on the F1 it works as it should with aperture showing DOF when DOF preview pushed out. After mounting with adapter on the RP there's is no aperture movement when turning the lenses ring. RP menu set to exposure enable, I'll take several exposures with f/1.2 and then to f/16 and nothing changes with exposure or DOF. Perhaps I'm missing something in a menu setting.
 

Oren Grad

Member
OK, so it should be easy enough to tell whether the adapter is properly setting the aperture lever - just take the combination off the RP, look through it and twist the aperture ring. There's no mechanical linkage between the RP and anything you mount on it, so there's no way any RP menu setting could make a difference in what a mechanically-controlled diaphragm is doing.
 

jdphoto

Well-known member
OK, so it should be easy enough to tell whether the adapter is properly setting the aperture lever - just take the combination off the RP, look through it and twist the aperture ring. There's no mechanical linkage between the RP and anything you mount on it, so there's no way any RP menu setting could make a difference in what a mechanically-controlled diaphragm is doing.
Exactly!
Ok, I did mount the FD lens on the Novoflex and RP. When the lens is fully turned to the right it "clicks" into place as it should. However, in that configuration it does not work, but turning the lens to the left as it dismounting the lens,(between the indicators on the adapter and lens) the aperture blades work perfectly. This is a workaround, but certainly not very secure. I contacted the dealer and they'll exchange it. Hopefully this works as Novoflex's products are excellent quality!
 

Oren Grad

Member
OK, defective adapter. Hope they can get you a replacement ASAP so you can get back to enjoying the lens fully on both cameras!
 

jdphoto

Well-known member
Update...
A little bit of user error and a bit design flaw from Novoflex too. I realized the red dot on the adapter is slightly off when mounting on the the RP, so if you align the red dots as written in the manual, the adapter does not engage the pin on the RP's lens mount allowing the aperture to work correctly. However, if you mount the adapter slightly to one side and not aligning the red dots, the adapter and and lens mount perfectly allowing full aperture control. Perhaps during painting of the Novoflex the red dots on this particular adapter were slightly askew. It works great now and love FD lenses on a Canon EOS R/RP.
 
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