View Full Version : Bag Bellows

Dave Schneidr
4-Apr-2001, 01:07
It's time to replace the bellows on my old Omega 45. The camera must be 30 years old plus the fact that I have used the bellows rather abusively by attempting t o use rise and tilt with very wide angle lenses. Which brings me to my question. I am concerned that a new standard bellows would have the same movement limitat ions so perhaps I should get a bag, but then I would give up some length. Has an yone attempted a home made bag bellows of longer than usual length? My thought i s to use a conventional four corner bag bellows design but to make it large enou gh to extend to 400mm or so. I know the problem would be sag at the long length. If a stiffer fabric were used would the addition of a hoop spring at the center keep it erect? A circular spring made from piano wire was my thought. I would l ike to have just one bellows to cover 75 to 300mm lenses plus the convenience of not having to change or carry bellows.

Scott Walton
4-Apr-2001, 17:16
Dave, that is an interesting thought about the piano wire. Theoretically it should work if you could position the wire and somehow secure it so that it doesn't move. With my Technika I would worry about folding and closing the camera... Good luck, Cheers, Scott

Dave Schneidr
4-Apr-2001, 17:36
I have a mono rail so closing is not an issue. My thought was to put the piano wire inside the bellows, perhaps a z-fold seam at the circumference of the bag. The piano wire could be bent to a coil larger than the actual bellows and then compressed down to fit. The effect would be to keep the middle of the bag fully extended regardless of the extension. The weight may cause it to sag at the middle but I could support it from the rail underneath.

John Hennessy
5-Apr-2001, 01:02
If you get the opportunity, look at someone's Technikardan compendium lens hood. It has a continous piece of steel wire sewn in at two spots. The total length of the wire appears to be about 1.5 x the circumferance of the hood material (which is not pleated like most hoods but is more a bag bellow.) It works as you might expect. The wire holds the material out of the way when partly collapsed and the material bends the wire flat when fully extended. But of course the hood is only about 100 mm long.