Posted: Wed Sep 08, 2010 7:17 am Post subject: Re: canon fd lens and aperture diameter problem |
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martyn_bannister wrote:
fstop wrote: |
Hello.
Can somebody suggest how to debug a wrong aperture closing problem in a Canon 50 mm f/1.8 fd lens?
It appears that when mounted on a camera and set to f/16 (manual mode), the lens does not close down enough to the correct value during exposure (it closes down to only around f/11 or f/13). But when I depress the DOF preview slide button on the camera with lens aperture ring to f/16, the lens appears to close down to the correct value.
Is this problem with the lens or should I look towards the camera body for a solution?
Thanks. |
Don't know this exact lens, but very often the aperture housing can be rotated to set the manual aperture against the markings. If the screws holding this have come loose then this might be the result? Usually easy enough to cure by removing the rear of the lens and checking, but doesn't usually involve disturbing the glass or the focus helicoid.
Sorry for the generality of the reply. Maybe someone has this exact lens and can be more definite? |