In article
>On Thu, 6 Mar 1997, David Brian Ritchie wrote:
>> Second, I do not get what you are saying --
>> I am sitting here looking at my F3 (an Ai camera) -- I have a 35mm Ai lens
>> and a 200-600 non-Ai Auto-Nikkor lens.
>> Both fit very nicely on the camera and do not break anything. The
>> difference
>> between the two lenses is that on the F3 there is a ring concentric
>> with the F Bayonet Mount which engages a plastic extension on the aperture
>> ring of the Ai lens to tell the camera the F-stop setting. The non-Ai
>> lens lacks this feature, but placing the non-Ai lens on the camera simply
>> does not engage the feature -- there is no mechanical interference. There
>> is also an engagement pin didengage function which allows you to lift the
>> pin out of the plane of contact with the lens (I guess for some odd lenses).
>Of all the AI or better bodies, only the F2, F3 and F4 support this
>feature. The F5 can be modified. Other bodies can't.
>You're confused because you happen to have one of the bodies that
>supports non-AI lenses.
>Modifying them to AI still makes sense, though; you will be able to meter
>at full aperture.
Hmmm, actually there is something else involved... DBR apparently has a good grasp of the concepts, but appears to be assuming that since the AI pin does
not need to be raised with his particular non-AI lens to prevent damage (the non-AI versions of the Nikkor mirrors and PC lenses also fit fine on AI bodies), that all non-AI lenses are like that, which is not true... Also (as with the mirrors, PC's, and other lenses slower than f5.6), AI'ing makes no sense with his lens, since the meter cannot function properly with it even
if the correct lens AI tab were made (harder to make, when there is no
material to cut away to form the ridge...), since the meter will not couple properly to lenses slower than F5.6. The metering options: stop-down
metering (holding the DOF button in during metering), and using a hand meter. BTW, F2A, F2AS, FM, FE, F3, and F4 bodies allow raising the meter AI tab for use with non-AI lenses (which can then be metered using the stop-down method).
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