Today I am starting work on a 4x5 reducing back for this camera. The camera is so lightweight I think it could be a wonderful option (for me, anyway) for a lightweight 4x5 point 'n shoot, and I want the option to use 4x5 color films. I could look for a 4x5 model of the Cycle Poco, but I've already got this 5x7, and adding a RB seems like a relatively easy--and fun--mod.
I got five layers (mostly) ripped and chopped for the 4x5 RB frame.
First layer is 1/8" craft plywood, 8 3/8 W x 6 1/4 H. This RB is different from others I've done b/c this camera has an internal spring and bar for the original 5x7 gg frame, and the 5x7 film holder slot is built into the camera body. I had originally planned to route slots in the top and bottom of the mahogany layer for the original spring bars, but I couldn't manage it on my table saw, so the plywood layer is Plan B. I need a 1/8" layer to fit under the spring bars. Plywood should be sufficiently strong to withstand the repetition of changing out with the 5x7 back over time.
Next, 1/4" mahogany.
Then 1/2 balsa for a spacer.
Topped with 1/8 x 1 basswood "runners" for the film holders. Still need to do more work to carve out for the film holder rib as well as fill in underneath the rib.
The fifth layer will be 1/2 x 3/8 basswood or mahogany for the U-surround light trap.
Next: staining and gluing.
Glued up the first three layers today. Too heavy. Realized that adding the base plywood layer make the 1/4 mahogany layer redundant.
Back to the drawing board...
Fortunately, all the pieces to be scrapped were from my scrap wood from older projects, and I've got more on-hand.
Learning by making mistakes. My usual wood-working MO.
I am sure you will impress!
Tin Can
Hah. Thanks, Randy.
Persistence is my super-power.
As is the case for everyone here.
Nothing about LF is easy. Maybe that's why we love it.
Okay, round 2. I got the main part of the new spring RB and the gg frame ripped, chopped, and glued.
Lots more to do sanding, staining, painting and adding metal springs and gg clips, and frosting the acrylic gg.
Nice to get this much accomplished, though. Everything fits--back to camera, gg frame, film holder. Just rough at the moment, but it will smooth out nicely.
Also, I will add mahogany veneer to the top of the gg frame.
As an added bonus for this project, I rechecked my 14" lens (https://www.largeformatphotography.i...=1#post1543515) and discovered it will cover 4x5 w/o vignetting. Pretty cool (I think) to be able to shoot a 355mm lens on 4x5 on a 2lb, 125 year old camera.
Last edited by Michael Roberts; 15-Sep-2022 at 19:06.
Finished fabricating the wooden RB and GG frame. Just need to apply film to the acrylic and fabricate the metal springs....
The back is 1/8 plywood with 1/2 balsa on top to provide room for inserting/removing the smaller 4x5 film holders, then 1/8 basswood "runners" for the film holder, and 3/8 x 1/2" mahogany surround. The underside is 1/8 x 1/2" basswood for a light trap. The GG frame is two layers of 1/8 x 1/2" basswood, with top layers of 1/8 x 3/8 basswood and 1/32 mahogany veneer. I sanded the underside of the GG frame down to a thickness of 5mm to get the correct T-depth to match the 4x5 film holders. I used flat black paint on the underside and glossy black to cover the ply and balsa, a little bit of red mahogany stain and two coats of clear poly for the mahogany. I omitted the stain on the surround, so the whole back has sort of a tri-color look--glossy black base, natural mahogany and stained mahogany.
Done, except for adding the gg clips and testing.
Camera weighs 2lb 8oz with lens and 4x5 reducing back and can handle 3 1/2" to 14" lenses. This will be great for long hikes.
Nice!
Tin Can
A quick point of correction: Glass plates in general have always focused the same distance as film. Or to more correctly say: the standard depth for a given format from the mounting surface of a film holder to image plane was standardized on the depth for plates..as of course sheet film adapters were designed to do so.
The story would stop there, but Autochromes complicated the issue of parfocality with the ground glass. The ground glass could be reversed for shooting Autochromes (which were loaded with the emulsion side facing away from the lens). In this way the photographer did not have to compensate with a slight shift after focusing. I think it was also possible to have a camera back set up specifically for Autochromes, but have not seen any record of that.
So an antique plate camera with the ground surface towards the rear may well have been owned by a photographer who shot Autochromes.
Newly made large format dry plates available! Look:
https://www.pictoriographica.com
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