Canon F1-N won't stop down

[steven_d._johnson]

<p>Canon F1-N low miles, a good user. No problems in the past. I now find that it won't stop down any three OEM Canon FD lenses I always use. The lenses stop down just fine in AE or manual mode on my AE-1 body, under varying light conditions. Any of the lenses will not change their aperature when the shutter is fired, either in AE or Manual mode when mounted to the F1-N.<br>

I read the Owner's Manual for the F1-N and I cannot seem to figure out what I'm doing wrong. I have tried stopping down both in AE and in manual. Cycling the depth of field preview does not change anything. I have replaced the body battery, checked it with the camera's battery check function, it's OK. I have a fresh set of batteries in the FN motor drive. I note that one of the instructions states that the motor drive must be attached for the Shutter-priority AE function to work. The problem occours with or without the motor drive attached. This camera is equipped with the AE Finder FN.<br>

I need input on why the body won't stop down the lenses. Something in the camera failed? Or did I miss a setting that I might have earlier disturbed?<br>

Thanks!</p>

[feanolas]

<p>It is not clear what happens when you use depth of field preview: does it work then or not? If not, you can try without a lens to see if something prevent the movement of the actuator.</p>

[steven_d._johnson]

<p>The Stop Down Slide fails to actuate the aperature.</p>

[steven_d._johnson]

<p>I'm sorry, that wasn't enough of a response. The Stop Down Slide (depth of preview) fails to actuate the lens aperature with a mounted lens. With the lens removed, the Stop Down Slide does actually move the actuator tab. However, the camera itself will not operate the actuator tab. I can see it give very slight movement, but no travel. I note that on the AE-1 full travel and movement is achieved, using both the shutter release and by depth of field preview.<br>

Is there a function on the F1-N that I may have set that would prohibit the actuator tab from doing its job?</p>

[steven_d._johnson]

<p>JB Fischer, thanks for your suggestion about the stop-down operation. In reviewing, I concluded that the Stop Down Slide was unlocked, and that is what was causing the lenes to not stop down. Unlocking the Stop Down slide disables the automated function of the actuator in using Stopped-Down (fixed-index) metering. It functions correctly, and I have locked the Stop Down Slide. The lenses now operate as I like. </p>

[chris_waller]

<p>As an F1 user of many years, I would emphasise that the stop-down slide must be pushed in before lenses are either mounted or removed. Mounting or removing lenses with the stop-down slide out will result in the problem you mention and may cause damage.</p>