Canon A-1 not closing aperture all the way

[altim]

I have a Canon A1 that only closes the aperture blades down to around the largest 1/5 of the apertures of the lens, and then stopping it down further does nothing. This is being tested by locking the dof preview button down and using some FL lenses.

I tried the same lenses on a different A1 body and they stop down all the way. I checked the distance that the aperture lever moves on both the working and the non-working body and they appear to move about the same distance, any ideas what else I could look at?

 

[dnjl]

Did you advance the film lever prior to mounting the lens? If not, try dismounting, cocking the shutter and then remounting. Just a thought.

 

[altim]

Did you advance the film lever prior to mounting the lens? If not, try dismounting, cocking the shutter and then remounting. Just a thought.

Hmm interesting...that fixed the problem. Why does this work?

 

[John Koehrer]

look into the mirror box. there's a small lever on the right hand side.
cock the camera and trip it and the lever will move a few mm. cock it and trip it with a light pressure on it and it will travel all the way to the bottom.

It's part of the metering system that tells the electronics what the f stop is.
It's likely that you changed a lens before this was reset(cocked)

 

[altim]

That is awesome, thanks for the info everyone. I always enjoy learning something new about cameras