rear lens element to focal plane distances for different format cameras

Started May 20, 2012 | Discussions thread
Joseph S Wisniewski
Forum ProPosts: 33,980Gear list
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Moving the body behind the lens
In reply to tektrader, May 23, 2012

tektrader wrote:

I expected the Russian lens wouldnt be quite there. So thanks for confirming that.

Any time.

Interesting about moving the body behind the lens. I am not quite sure how you are going to cope with the focal plane distance change.

Right now, the only wide I use with it has had its rear mount removed so that it won't collide with the camera's front mount. The rest of the lenses are "short mount" macros, like Leitz Photars and Zeiss Luminars. Regular mount macros work fine at at product and macro distances, just not at infinity.

The goal is to remove the mount and mirror box from my 5D II so it can get close enough to the front standard so that any lens will work. I'm picturing tilting the camera behind the Nikon 14-24 or a Zeiss 15mm.

I would assume you would have to place some sort of shift mech between the lens and the body.

I place the shift mechanism under the body and the lens board.

  • Tilt comes from a pair of Melles Griot goniometers. That's the hard part to deal with, those things are about $600 each.

  • Swing comes from a pair of Benro PC-0 pan heads. Amazing how precise those $90 gadgets are.

  • Shift is Velbon mag sliders, the end driven ones.

  • Rise/fall is a low profile Melles Griot.

  • Focus is a pair of independent Velbon racks, taking a lesson from the dual racks on the ARCA telescoping rail.

  • Under the mail rail is a Benro GH-3 for nodal panning, and a Novoflex Castle-L for mail rail focus.

All in all, it has 14 motion controls.

Once I convert the 5D II, it will be a full 35mm format view camera.

Wonder if you could put the PB-4 on backwards ?

It would be difficult.

I was even thinking of buying a PB-4 and hacking it so it can tilt as well as swing. Mechanically it can be done.

Yes, I even figured out how, once. The 440mm Melles Griot or Opto Sigma goniometers have 35mm from the baseplate to the rotation axis, essentially perfect fo the PB-4. The 40mm are less than half the price of the 65mm I used on my rig, and if you look for a used one on eBay, you often find them for around $100.

You would think that with all the clever camera companies out there some one would have tried to come up with a good substitute to a bellows camera for 35mm.

Maybe it should be us Joe................

Maybe.

If I could just figure out how to make more like mine without them costing $3,000 each. Lenses are still the problem. Something has to give, either the lens rear mount or the camera's front mount. It's more versatile if you do the camera.

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Rahon Klavanian 1912-2008.

Armenian genocide survivor, amazing cook, scrabble master, and loving grandmother. You will be missed.

Ciao! Joseph

http://www.swissarmyfork.com

 Joseph S Wisniewski's gear list:Joseph S Wisniewski's gear list
Canon EOS 5D Mark II Nikon D90 Nikon D2X Nikon D3 Nikon D100 +43 more
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