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View Full Version : Apo-Sironar Digital 35 or 45mm on Sinar F2



Jeremi Buczkowski
4-Jun-2010, 06:54
I recently bought MF digital back (Phase One P25+) together with FlexAdapter and Kapture group one shot cable, with commercial architectural photography in mind.

Until now I was using Schneider SA XL 58mm lens on Sinar F2 with 4x5' film occasionally shooting 6x7 cm. While I began using this lens on the digital setup I noticed chromatic aberration and rather law resolution. Because of that I am after a lens like Rodenstock Apo-Sironar 35 or 45 mm.

The question is, if it's possible to mount 35 mm or 45 mm (I would rather go for the shortest possible) on the Sinar F2 with recessed lensboard and bag bellows, and how deep the lensboard should be to accept such a lens (and what source should I choose: e-bay, Kapture group, S.K. Grimes ?).

Does anybody had the same problem and resolved it successfully ?
This is very important question for me as I don't have possibility to go to the specialist shop to test different lenses in my country [Poland] and will have to make decision based solely on my readings.

carverlux
4-Jun-2010, 09:54
Jeremi,

What you want to do is possible, and I would suggest that you start solving each of the challenges one by one:

1. Flange focal distance for infinity - with recessed boards this can easily be done. Many of the new boards made in China are deeper than original Sinar boards, so this is likely not a big problem.

2. Focusing the lens - while the F2 and P2 or P3 can focus the front or rear standard bearers with the frames on them, the precision of the F drive and even the micrometer P2/P3 drive is not fine enough for the extremely short focal lengths like 35 or 45 - at least to me. Unless you have perfectly adjusted gears, they slip just enough to get you off focus when you least want it. You should really consider helical mounts which along with the lenses should the be mounted on the recessed boards as in 1. above

3. Clearance for your fingers to adjust the aperture, shutter speed, cock the shutter and most importantly attaching the Kapture Group cable release to the shutter. Now the problems all come together as in 1. and 2. above.

The recessed board must clear all these things or it will simply get in the way and prevent you from taking a picture. You should either explain this well or take a few pictures to illustrate this to the recessed board supplier.

4. Once you have the recessed board completely sorted out, you will need the later version of the Sinar double-pleat Wide Angle bellows (Sinar 455.46) or the standards cannot rise and fall adequately for the 35/45 lenses when an ordinary bellows is so compressed.

With all this done, you should be in very good shape. Or it could frustrate you to the point of wanting to buy a new camera especially made for architecture...like Sinar's own ArTec or the fabulous ArcaSwiss line. Stay with it and it will reward you - I did.

Good luck,
Carver

Bob Salomon
4-Jun-2010, 10:09
You will find that a camera like the Linhof Techno which is all geared and uses the 23mm on a flat board would be much better for digital work on location. You might check the article in last months British Journal of Photography which specifically addresses what you are trying to do.