On Sat, 04 Apr 2009 15:48:39 +0200, Rol_Lei Nut
wrote:
: Robert Coe wrote:
: On Sat, 04 Apr 2009 19:59:43 +1300, Apteryx wrote:
: : goldtech wrote:
: : Hi,
: :
: : Been trying to understand the compatibility issues of nikkor lens/
: : nikon camers.
: :
: : Say I have a Nikon f2as DP-12 finder. If I use a pre AI lens it would
: : work but I would have stop-down light metering?
: :
: : Yes. At least I think so. I have an F2AS, but no pre AI lenses. The
: : finder allows you to flip up the AI metering tab so as to mount a pre AI
: : lens without damage, but has no prong to be captured by the pre AI
: : lens's metering fork to tell the camera what aperture has been pre-set
: : on the lens.
: :
: : But if I used a pre-AI lens on a Nikon F Photomic then the metering
: : would be that the lens would be largest F-stop until I shoot? Or would
: : it be stop-down as I meter?
: :
: : I think the former - since I believe the F's Photomic finder (and some
: : older finders has the necessary prong that the F2AS lacks (but I've
: : never owned an F)
:
: I never owned an F either, but my F2 did have a prong to engage the fork on
: the lens, which remained at full aperture until the shutter button was pressed
: (and returned to full aperture as soon as the exposure was complete). That
: feature may have been new on the F2; my recollection is that the front
: overhang that contained the prong didn't exist on the F's finder. But that
: recollection could well be wrong.
:
: One thing I am sure of is that you had to be careful how you mounted the lens.
: If the prong was in the wrong position, the fork could push it out of the way
: without engaging it, and the aperture settings wouldn't get passed to the
: finder.
:
:
: Ye Gods!
:
: And if you set a non-AI lens to f/5.6 you'll get warts on your hands...
:
: What a pearl of misinformation!!!!

I suppose it's possible. My own impression is that the misinformation lies
only in things you think I said but didn't.

: BTW:
: The F FTn and the non-AI F2 Photomics are conceptually the same (at
: least as far as the prong is concerned).
: Nikkormats and F Photomics prior to the FTn required setting the lens to
: 5.6.

My wife's Nikkormat did have to have the lens set to f/5.6 when attaching it
to the camera; my F2 didn't. But on the F2 you did sometimes have to twist the
setting ring back and forth to make sure the fork engaged the prong.

: The prong had NOTHING to do with the so-called auto-diaphram mechanism
: (which was NOT new on the F2).

The auto-diaphragm mechanism would have worked without the prong, but that's
hardly the point. Without the prong, the lens wouldn't have been able to
inform the camera of its aperture setting, and the metering system wouldn't
have known how to account for the effect of the automatic diaphragm.

Anyway, I mentioned the auto-diaphragm mechanism only because it was part of
the OP's question.

Bob