Hi

I have a question. I have 3 lens for my nikon, 24mm, 50mm and a 105mm. When i change the aperture on my 50mm and 105mm, the lightmeter reading changes. Now w/ the 24mm, the lightmeter reading does not change no matter if i racked the aperture to 16 or 2.8. What should I do? How would I meter a scene? Should I assume the reading that is present to be that of f2.8?

thanks, ken

-- Ken Kwok (kk353@yahoo.com), February 17, 2002

Answers

The answer will depend on the camera in use.

-- Frank Uhlig (uhligfd@auburn.edu), February 17, 2002.

nikon fm3a

lens: nippon kogaku 24mm 1:2.8 nikkor n

-- Ken Kwok (kk353@yahoo.com), February 17, 2002.

Sounds to me like it might be malfunctioning. What happens when you take it off the camera and close the iris down, do the blades close? There are also levers on the back of the lens that make the open- aperture metering interface with the camera, maybe one of these is bent or broken and is not closing the iris. Does these levers look the same as on the other lenses you have-they should.

Have a little fiddle with it and report back.

Steve

-- Steve Phillipps (steve@redvixen.freeserve.co.uk), February 17, 2002.

iris blades close down as I rotate the aperture ring

there's a lever on the back that opens up the iris when i flip it up.

-- Ken Kwok (kk353@yahoo.com), February 17, 2002.

oh yeah, and they look the same as all the other lenses that i have.

thanks

-- Ken Kwok (kk353@yahoo.com), February 17, 2002.

Ken, What happens when the lens is on the camera and you press the depth of field preview lever (if it has one)? Steve

-- Steve Phillipps (steve@redvixen.freeserve.co.uk), February 17, 2002.

the screen darkens

p.s I really appreciate so many people helping me!

-- Ken Kwok (kk353@yahoo.com), February 17, 2002.

It sounds like you have a non-AI lens. This lenses will only meter normally on a body, like the F2, with an index pin under the prism housing.

The F3 requires that the lens index with a ring around the lens mount. You can have the lens modified for use on your camera, or you can use "stop down" metering with this lens.

I doubt that either the lens or the body are malfunctioning.

-- Ed Farmer (photography2k@hotmail.com), February 18, 2002.

You have an early, non-AI Nikkor if it's stamped "Nippon Kogaku" and won't meter-couple with your FM3A. You can actually damage the AI tab on your camera with a non-AI lens, so don't force it. You've got two solutions:get the lens AI-d by someone competent or get a camera that accepts the older lenses.BTW, this lens will *not* work in stop-down mode on this body.

-- Gary Watson (cg.watson@sympatico.ca), February 18, 2002.

cool. thanks. I just sent it to get AI'ed. Cost 'round $60.

thanks, again. ken

-- Ken Kwok (kk353@yahoo.com), February 18, 2002.

Gary,

Just curious, why won't the lens work in stop down?

-- Ed Farmer (photography2k@hotmail.com), February 19, 2002.

If there's any interference whatsoever between the aperture ring and the AI coupling tab, it will damage the AI coupling tab on the camera. The damage may happen quickly, or it may take time for the back-and-forth motion of the aperture ring to wear away at the AI coupling tab.

If there were no absolutely no interference between the AI coupling tab and the aperture ring, then the lens would work fine in stop-down mode. Actually, it might be able to meter properly in stop-down mode anyway, even as it's destroying the AI coupling tab. This is NOT recommended, of course! It's also possible that the aperture ring could partially catch the AI coupling tab and move it in unpredictable ways, leading to unpredictable metering.

Best bet is to NEVER mount a non-AI lens to an AI-only camera like the FM3a. Either get it converted, or use it only on cameras that have either flip-away AI tabs or the old style pin and yoke meter coupling.

-- Richard Cochran (rcochran@lanset.com), February 19, 2002.