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Re: [OM] 2-4 screen and shift lens

Subject: Re: [OM] 2-4 screen and shift lens
From: sunil manga <ameteep@xxxxxxxxxxxxxxxx>
Date: Mon, 25 May 1998 12:52:43 +0530
Hi Richard!
It was nice to read your OLY 35/2.8 shift letter.
For serious 35/2.8 shift users, here is something interesting.
While reading the old ;TIME-LIFE series book on The Camera' , it has been
explained with illustrations, on 'How to shoot a shot with amirror in the
picture.'
My immediate problem was, to make a reproduction of a 50 year old
glass-framed photograph. It was clear that tking the photograph ou of the
frame was impossible, and photographing with a Polariser not good enough.
So the 'VIEW CAMERA' principle: shift the lens and focus on the photograph.
AND 'magic' NO reflections of Camera& lens.
TRY IT, it Works!
Sunil Manga.

Richard Schdtzl wrote:

> Hello Olympians,
>
> I had recently the chance to play a little bit with an 35mm/2.8 Zuiko
> Shift. I was an near mint lens and the shifting mechanism was very
> smooth but firm enoug to hold the lens. The special cross "dovetail"
> shifting mechanism allows to make the best use of the existing image
> circle. An result is the maximum shift of 13mm down, were all other
> shift lenses allow only 11mm.
> The amount of shift relativly to the negativ/slide size determins the
> relative gain of height you achieve (not the angle of view).
>
> For example: If your negativ has an height of 24mm and you shift the
> lens for 12mm, then your relativ gain of height is 50%. This means if
> your field of view has an height of 10m then  gain 5m (comparable with
> the use of an 5m ladder).
> Nearly, in fact you have avoided perspectivic distorsions, but you
> haven4t changed the perspective (which is determined by your point of
> view), that4s why the nomination PC (perspective correction) lens is
> incorrect (not PC, ;-)  ).
> It4s like using an part of an biger, wider angle negative. So the
> distortions of the shifted lenses are the same as in the corners of an
> respective lens (for the 35mm Shift Zuiko, an 24mm wideangle).
>
> Shifting has some consequences for your view through the finder. Shifted
> down, an part of the image rays will be projeced under the mirror,
> resulting in an shadow in the finder. Mirror depending metering will be
> screwed up to. Olympus is advivceing to meter with unshifted lens.
>
> One realy shocking experiance was, when I was looking through the finder
> of an 2-4 screen equiped OM at max shift. There were enormous colored
> fringes on contrasty edges.
> After the first panic, some herretic thougths about the abilitys of the
> Olympus lens designers and some swearing, I did a cross check with an
> standard screen of the 1 series and it was much less obvious. So the
> 1-10 grid screen seems to be the best choise for this lens.
> For a further investigation I mounted the camera with lens on an
> copystand with a matte screen on the film plane and the shutter fixed on
> B.
> There were no noticeable color fringes at 4x magnification. But there
> was a noticeable fall of image quality in the corner at max shift. It
> turned out, that, at least to a part, a curved field of focus was the
> reason, which could be confirmed with refocusing.
> This is somewhat unconveniant if you consider the intended use of such a
> lens. The curved field was not noticeable unshifted, but you4re paying a
> lot of bucks for this lens, to use it shifted.
> Stoping down to 8-11 helped much to get the whole plane in focus at max
> shift.
>
> So much to my preliminary results.
>
> Richard
>
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