Re: Seitz Roundshot 220VR lenses

[Simon Nathan <simonwide@xxxxxxxxxxxxx>]

Michael Stoll wrote:

>Once again I am trying to match a new lens to my Seitz Roundshot 220VR camera.

...maybe we could set up a page with all ever measuered lenses ...

>The manual descibes a " shoot some film and judge with your eyes" procedure
>to find the "exact" focal length.
>
>There is also a "distance to mainplane h value" for each lens when entering
>information into the camera's controller.
>
>Can someone explain what this "h" value is and how it is calculated for a
>lens that is not in the manual's lens list???

Seitz offers to measure a certain lens for you. Just call them.

>Also is it practical to use zoom lenses?
>I'm trying a Nikkor 20-35 AF-D lens with the barrel taped down on the 24mm
>mark.

... Mr. Seitz told me, not to use such lenses, because of two reasons:

1) you are never really aware of the focal length, even not with
fix-focus-lenses,
   as you can easily see from list at the manual's back. I. e. my
50mmNikkor (1.8)
   has to be set up as 52.1 or something like this ...

2) when spinning very fast, the leens could change its focal length by ...
    (... gosh, have to consult my dictionary...) centrifugal power (...ups,
could have
    have known that ...).

>This lens covers the full height of the film at 24mm, but not at 20 mm.

I am fighting with the same problem @ 14mm-Sigma. There are several
solutions: the best I've seen is @ Gene Woolridge's 220VR. He is using
a modification, made by Hulcher (http://www.hulchercamera.com/).
It allows to use Mamiya-medformat-lenses and even shift it (not suitable for
QTVR but nice when shooting in gardens with high trees ;-)).
you can cut down your trial and error trials by asking respective lens makers for circle of coverages for, say, two f,- values. if the answer is that  "it covers the format" it is a brush off answer. yamaki, sigma designer/president will tellya. nikon japan has all of this info. canon won't answer    because that information isn't nessary. to hear more on this contact me directly because we must not bore tranny-printing computer tecki's. simon nathan   and by the way guess who chose mamiya 645 35mm lens for first hulcheramas and why? simon did.

Gene is monitoring this list, too.

But one questions seems not solved to me until now: Do I get a larger
vertical field
of view with the hulcher-modification and the shortest available mamiya-lens,
than when using the shortest 35mm-lens that covers the full height?

Anyone any ideas or even better: proofs?

>Is anyone using a fixed Nikkor 24mm and does it cover the full height of
>the film?

I am using a 28mm-Sigma and its not as sharp as my 50mm-Nikon which I
really love!

Cheers, Michael.

_______________________________________________________

...hase...auto...adda... (Paul Anton Stoll, * 10.01.98)
_______________________________________________________
Werder & Stoll. Buero fuer Gestaltung
Claudia Werder, Designerin MA (RCA)
Heinz Michael Stoll, Diplom-Designer (FH), AGD, SND

Ebertstrasse 8
D-72072 Tuebingen/Germany

phone           ++49 (0) 7071 / 360303
fax             ++49 (0) 7071 / 360325
E-Mail          mstoll@xxxxxxxxxxxxxxx
WWW (docu-site) http://www.cityinfonetz.de/stoll/
WWW (QTVR-site) http://www.cityinfonetz.de/stoll/
ICQ#            17446938   (see: www.mirabilis.com)
_______________________________________________________