Converted canon 100mm fd

[John wells]

Hi there

I wonder if someone can help, I bought some time ago the above lens that had been converted to EF mount, at the time I understood it had been done by the lens doctors.

I rarely use it and got it out to play with today to find it seemingly locked wide open, no movement in aperture blades.

I'm moving the aperture ring and the focus ring and both move well, no friction or resistance but no visible difference in shot be it at f2.8 or 32.

Do I have a dud? Is there anything I can do?

John

 

[Canon Bob]

I believe that the Lens Doctor conversions still have the option for wide open focusing with the open/lock lever for aperture control....does yours have this and, if so, is it in the correct position when you stop down to take the shot?

Bob

 

[John wells]

Where would it be bob? At the point it connects to the camera?

 

[Canon Bob]

Sorry John, I've just been refreshing my knowledge of Lens Doctor conversions and they now seem to use some hydraulics! (FVA) to enable smooth operation of the aperture in cine applications.

Have a look at the Lens Doctor website and see if yours is definitely one of theirs.

Bob

 

[TimmyG]

With some of the FD lenses you had to mount it to release the aperture. Not sure how the conversion is done but have you tried putting it on the camera and then adjusting the aperture?

 

[John wells]

Yes it was connected but no visa Le difference in the shots, I'm sure it used to on my old 5d