Andrew Fildes wrote:
> There's a little trap in this one. Some have a ridge that depresses
> the button on the back of the lens to cancel out the 'auto' action -
> then it acts just like an Oly lens on the adapter. Sounds good,
> especially for those old M42 lenses without an 'auto/manual' switch.
> However, it means that you can't use the very last of the Pentax
> screw mount lenses as the ridge fouls the metering lug. Probably
> causes a problem on others like the Fuji's as well. I found that I
> couldn't try out my nice Takumar 200mm for this reason.
>
However, as I was going to post, there are other lenses that won't stop
down at all without the little ridge. Lenses that don't have an A-M
switch setting on the aperture ring, which includes all Tamron Adaptalls
with the M42 Adaptall2 that I have, cannot be stopped down unless the
auto pin on the back is pushed in by the little ridge.
No big deal for me, as I can simply use the Oly Adaptall and an OM=>EOS
adapter, but there are probably some pure M42 mount lenses out there
without an Auto-Manual switch, given the nmumber of variations made.
Looks like one needs both kinds of adapters to be able to be sure of
being able to use all types of M42 mount lenses.
Another thing to be aware of with M42 to EOS adapters is that they can
short out some of the electrical connections for the EF lenses. I only
know this to be true for the 300D I have, but assume it to be true of at
least all EF-S capable bodies, if not all bodies. Easy to remedy with a
piece of tape, but without that, one could easily suppose that the
camera body isn't working.
Moose
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|