Questions on design of my own 11x14 ULFgreenspun.com : LUSENET : Large format photography : One Thread
It's winter and that means more time to work on a new project. I plan on building a simple box camera for 11x14 with a few refinements that I would like to discuss.
The plan is for a reinforced box with a front portion that slides into the rear box for focus on rails and to have rear tilt and front swing and tilts. To achieve these movements is what I need input on.
My design is to mount the lens in a sphere that is "clamped to the lens board to allow for pivoting in all directions (similar to a tripod ball head. Once the desired position is achieved a pair of thumbscrews will lock down the sphere. I have done some preliminary research and have found a source for the "spheres" through a machine shop that says they can get such things custom made from aluminum about $100 each depending on size. I would have to manufacture the system to clamp but I have that designed already.
Question, since all pivots will be about a intersecting point on the lens board, will this not be as functional as similar movements on common design front standards for swing and tilt?
Second, inside the back of the box will be a plate mounted to pivots on the side of the box to allow for rear tilt of film plane. This plate when in vertical position will allow the film holder to be inserted through a 2 inch extension to the side of the box with a pair of spring loaded or maybe just flexible plastic light baffles to allow removing dark slide. directly behind this assembly will be attached the ground glass accesible by removing the back of the camera which is designed as a cap to be replaced to protect the GG and prevent any light leaks.
My final question is how much of the film needs to be covered by the rails on the film holder to hold it securely in place. I will be making my own single sheet fim holders, out of lexan or similar materials, I have a plastics company that can cut, machine any pieces I need. Also, what is the thickness of a common 11x14 sheet. I hate to waste one just to test the film holder.
I know, the whole thing sounds heavy, and unwieldy. But most of my work with this camera is accesible by vehicle. I could search for a rebuilder but I fear that eventually, (but I hope not), that these large film sizes may go by the wayside. I estimate this camera will cost about less than $400 without lens. Comments, suggestions, criticism please and thanks in advance.
-- James Chinn (Jchinn2@dellepro.com), January 02, 2002
James: How do you plan to get a light seal between the moving front box and the rear box? With your aluminum ball design you will get only axis lens tilt, no rise or fall or shift. Lenses that cover 11x14 will in any case have limited room for movements. You might be better off purchasing an 11x14 camera back with ground glass from an old studio camera, and starting to build the rest of your camera aaround this. I've seen such cameras on e-bay, which were inexpensive but non functional. Good Luck
-- Lewis Lauring (firstname.lastname@example.org), January 02, 2002.
You'd be much better off following the example of a simple Cadet camera than what you propose. Two L arms and standards on a simple rail is all you need. For a rail you could use a Bogen dual camera setup with dual clamping sliders. I forget the #. It's in their catalog.
-- Wayne Crider (email@example.com), January 02, 2002.