This is my favorite idea. Have you seen it done? I was thinking four cables, but the bottom can sag all it wants. Could the cables even be threaded through loops on the outside of the curtain? Like a curtain rod in a window?
What I'd like to build is front and rear standards that slide along a table for a ULF wetplate camera..
Originally Posted by bobbotron
When you come to your senses do yourself a favour and contact http://www.custombellows.co.uk/
I don't see why that wouldn't work. You could add some eyelets, pulleys, or something with holes in it to thread the cables along the tops of the standards. You might think about tying them tight at one end, and put a heavy weight on the other. That would keep the cable tight. Or you could come up with some other kind of spring loaded tensioning device. Perhaps something similar to a tape measure or vacuum cleaner power cable. It'd be wise to come up with some kind of method of keeping the bellows from drooping so you can focus without having to worry about the bellows falling in the way. Then just hang the bellows like a shower curtain. You'll want to hang them a good bit above the standards to allow them some room to droop before they fall into the path of light. The hard part will be coming up with a way to attach the bellows to the rings that your run the cable through. You don't want to puncture the fabric if you don't have to, cause then you'll have a spot for light to leak through. Also, hanging them from rings should give the bellows some pleats that should knock down reflections from any stray or unwanted light.
Use air pressure to inflate a double walled tube.
Basil, I think a sliding box is probably a lot easier to make, if it is just going to sit on a table.
I keep coming back to this thread...thinking I can contribute something. Hmmm...my first DIY camera was an 11x14 monster featuring a nesting-box bellows. Weighed a ton and the only tripod that would work was the old Quickset (anything but!) "Gibralter," which would easily double as a building jack.
But the cloth and retractable line idea...I do seem to remember a very small device - like a pocket clip which looked and behaved like a very small retractable tape measure to keep pens and such "organized" (or whatever). At any rate, a couple of these attached to an upper part of a front or rear standard, to hold blackout cloth out of the way...hmmm - I can see problems with this.
Actually, a Home Depot 3-mil black contractor's bag, wrapped around the standards "whole" to get the full 6-mils of thickness, and wrapped loosely at first to allow for movements/adjustments then secured with black tape to block out light...would work in a jiffy!
Some years ago I made an experimental non-tapered bellows from stiff black craft paper (a sheet large enough for the four sides to be cut in one piece), where all the edges were reinforced using 1" wide black gaffers tape. After cutting out the one-piece pattern I then scored all the fold lines using a ballpoint pen before carefully creasing all the folds. Then I applied the 1" wide black gaffers tape to all the creases; the creases pointing outwards had the tape applied to the outside, while the creases pointing inwards had the tape applied to the inside. After all the creases were taped the two ends of the pattern (on the underside of the bellows) were joined with gaffers tape to complete the bellows.
The black paper is stiff enough so that it doesn't require stiffeners to be installed in each section, like you have to do with cloth bellows; while the light-tight cloth gaffers tape provides strength, flexibility and durability. This bellows is still functional to this day, and the tape has not yet come lose from the paper.
The only downside I can see from this design is that the paper isn't water-resistant, so you wouldn't want to get it wet.
~Joe
The photograph and the thing being photographed are not the same thing.
I think the best solution would be a long bag bellows, but maybe with a bunch of cardboard strips as stiffeners so it wouldn't sag. You could arrange them like an accordion's pleats. It sounds crazy, but it just might work...
"I love my Verito lens, but I always have to sharpen everything in Photoshop..."
I've wondered about a "Slinky" style arrangement where something like 2mm neoprene covers a concertinaring helix.
Lachlan.
You miss 100% of the shots you never take. -- Wayne Gretzky
Having made a non-tapering bellows about 11" square by about 48" long (I wanted magnification on 8x10 with an 18" lens, I know, crazy), it is tedious, hard to do well and the final minimal thickness was not something I'm proud of either, though. The project was predicated on absolute minimal expense. I used the opaque curtain material they sell at fabric shops---maximal dimension is 54" w/o seam in one direction by whatever length the roll is the other. It seems to be light proof in my use, though I've not done any rigorous testing for IR or even true opacity, honestly. It works to make pictures so far using about 100 speed film.
I've thought about making a bag bellows for this behemoth of an 8x10 to use shorter lenses and planned to follow the Sinar design more/less.
I've also thought through most of the ideas on this thread, mainly for studio cameras or ULF where super long lenses v. the size of the film aren't so easy an option. I'd thought that bungee cord material would put too much stress on the system, nesting tubes are too fragile and fussy and hard to source and have limited minimal length adjustment.
I tend to think that the best option would be something sort of like a bag bellows with tabs built in to take lengths of string/cord from front to rear standard and either tie off the string or use a spring loaded stopper like was typical on draw string bags back in the 70-80's when I did more camping.
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