View Full Version : Suggestions for LF/ULF (8x10+) back size for project camera?

John Schneider
7-Sep-2013, 22:37
I'm getting rid of most of my projects but I'm keeping my K-38 camera (1950s aerial camera using 9" roll film and producing 9x18 images). My camera is missing the back, so it's just a giant light-tight cone. The open area at the rear of the camera, accounting for any protrusions in the light path, is 10.75 x 17.625. I could easily mount an aluminum sheet there with a cutout for a spring back of some size.

What are some suggested film sizes that would work, keeping in mind the difficulty/cost in finding/making the spring back and sheet holders? I have an 8x10 back and holders, but that seems to be not worth the effort as opposed just using my 8x10 Arca

Daniel Stone
8-Sep-2013, 00:22
I'd do 7x17
•Richard ritter(to make spring back)
•Alan Brubaker(to make film holders)

Lachlan 717
8-Sep-2013, 01:47
I'd do 7x17


Oren Grad
8-Sep-2013, 08:01
7x17 is the obvious, easy fit. But why bother when there are plenty of full-function 7x17 cameras around, often at attractive prices?

How much does the cone weigh? How much would a completed 7x17 camera weigh compared to an existing Korona or F&S? Do you mind not having movements?

Is the point of doing it as a project camera just to substitute some of your sweat equity for cash, or would you like to use the cone to accomplish something that would otherwise be difficult?

I'd want to think carefully about just how practical/impractical it would be to push all the way to 9x18, before retreating to 7x17.

Tracy Storer
8-Sep-2013, 09:50
Get some 9.5 Aerial roll film and get holders made and do 9x18 !
With a 12-14" Dagor, you'll be in business, or to go extra wide, find a 212 Series V Protar.
Hard to tell how heavy it is from the photos, a lot of those castings were magnesium or other light alloys, be careful before doing any powered cutting / drilling / machining.

Oren Grad
8-Sep-2013, 10:25
How long is the cone? From the proportions, it looks as though you'd be constrained to a very long FL.

John Schneider
8-Sep-2013, 13:40
The camera is a thin-wall casting that weighs 21 lbs, so it's definitely either aluminum or magnesium. I've seen the aftermath of a magnesium fire (machining an AH-64 tail rotor gearbox casting, where the coolant ran dry), so I would definitely be careful. The basic camera is 30" long; this one also has the 6" add-on cone. I have a 750 Apo-Germinar and a 35" Apo-Artar so I'm set either way. My idea is to make an infinity-focused camera for a long f.l., and this way it would be one self-contained unit without bellows to catch the wind and with quick set-up. Of course I'll be the first to admit that I sometimes chase elegant but impractical designs.

8-Sep-2013, 15:48
A simpler option would be to get the film holders of your preferred size, then research some pinhole cameras for options for backs that hold the holders. I have used a pinhole camera like this http://www.pinholecamera.com/ which uses wooden cams (off center big dowels) to clamp down the film holder; very simple. It'd be simpler than a spring back.

Drew Bedo
10-Sep-2013, 05:28
I would think that it all depends on what spring back is available and at what cost. The availability of film holders might also figure into your decision.
Too bad the camera isn't complete: There was a roll of LF film on e-bay last week . . .9" x ? yards!

10-Sep-2013, 07:39
I would be tempted to stick a small, autofocus digital camera in the front tethered to a 'touchpad' screen in the rear

one gignormous 24 pound P&S camera

Daniel Stone
10-Sep-2013, 07:58
I believe I understand the reasoning behind your wanting to make a "bellows free" design.

Why not just use plywood and make a box? It'll be lighter, just as resistant to wind, you can make it a box-within-a-box design, so one box can slide into the other one, for focusing closer-up than infinity(still no bellows, just a simple box-in-box design...

just a thought.... the box-in-box design might also save some sq footage storage-wise.