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Re: [OM] m42 zuiko on Can*n

Subject: Re: [OM] m42 zuiko on Can*n
From: Frank Wijsmuller <wijsmuller@xxxxxxxxx>
Date: Wed, 23 Jan 2013 21:39:30 +0100
Thanks Moose. I think I understand the Oly pin very well, there is plenty
information available.

It is actually part of the diaphragm ring which tells the FTL body at which
diaphragm the lens is set. The FTL mount has a 'slider slot' to 'read' the
pin. It would not be impossible to make such an opening on an adapter, but
I wonder who has gone that or other ways.

I'm hoping Andrew can clarify if his trick left him with infinity focus.
And maybe there are some others who managed some solution (other then
filing the tab)...

Thanks, Frank.

PS  An instructive picture is here (scroll a bit) <
http://www.biofos.com/cornucop/ftl.html>



2013/1/23 Moose <olymoose@xxxxxxxxx>

> On 1/23/2013 7:13 AM, Frank Wijsmuller wrote:
> > Just bought one of these Zuiko's: <http://www.pbase.com/image/95819343>
> >
> > ... I would like to keep the pin *and* focus for infinity.
>
> I think you may misunderstand how the lenses work. "The M42-EOS adapter
> had to be turned down so that it cleared the
> aperture info pin on the lens. "
>
> I know nothing specific about the Oly FTL or its lenses. What follows is
> generic info about M42 lenses with auto
> aperture capability.
>
> That is not an 'info' pin, but an aperture operation pin. These cameras
> had no idea of the actual aperture setting.
> Unless the pin is pressed in, the aperture stays all the way open. The
> camera presses it in for TTL metering, if
> available in the body, and to close the aperture for exposure.
>
> Because this aperture pin operation was a sort of ad hoc adaptation, thing
> aren't always consistent.
>
> For example, there are two kinds of M42 adapters. One ignores the pin. The
> other has a flange at the back that presses
> the pin in as the lens is screwed into the adapter. It sounds like you may
> have cut away the flange on your adapter that
> does that.
>
> I have both kinds, as I have an old Tessar, with pre-set aperture
> operation, that protrudes too far back to fit in an
> adapter with the flange. The other nicely operates the pin on a more
> modern lens.
>
> If I fit a later lens with pin in the old style adapter, the aperture ring
> doesn't adjust the diaphragm, and it's always
> wide open on the Canon body.
>
> UNLESS, it's a lens designed for all bodies. I have an "Auto Image" brand
> 28/2.8 that has a ring behind the aperture
> ring with 'A' and 'M' settings. At the M setting, it pulls the pin in for
> manual aperture operation on cameras without
> auto aperture capability.
>
> Sooo ... Unless the Oly lenses have a Manual setting, you probably need a
> new adapter.
>
> Push My Pin Moose
>
> --
> What if the Hokey Pokey *IS* what it's all about?
> --
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