Size of bellows pleats please

[Barry Kirsten]

I'm about to start on a bellows for a new 5x7 camera build and thought I'd ask for guidance on the size of pleats. My Linhof 4x5 monorail has 10mm pleats and I'm thinking that 12-15mm would be about right for 5x7. Would one or two of you please measure your 5x7 bellows and let me know? Also how much bigger than 7" is the inside size of your bellows?

Many thanks,

Barry

[Steven Tribe]

Square or Taper Bellows?

[Jim Jones]

The width of the pleats might vary, depending on the overall compactness of the camera, the minimum bellows extension, and perhaps other considerations. On my 5x7 Burke & James the pleats are 15mm wide and the square bellows tapers from 170 to 105mm, which barely clears the openings for the back and the 5.25 inch lens board. On my 8x10 Kodak 2D the pleats are 17mm wide and the square bellows tapers from 240 to 145mm, which barely clears the openings for the back and the 6 inch lens board.

[LabRat]

One thing to consider is that with bellows that have wider pleats means that it will stack up better folded (if tapered) but be stiffer using extreme movements, while narrower pleats will allow more flex at extremes and more inside area for the lightpath, but tend to sag more...

Decisions, decisions...

Steve K

[Tin Can]

My 50's 5X7 Kardan Color has the finest bellows I have ever seen. Still perfect.

Square, no taper, folded corners, 13mm pleats, with now get this, football like ballooning on top and bottom only, to control sag. It's a thing of beauty. Very thin leather.

Internally and collapsed they are 7X7" in larger cast Alloy frames, but widen internally as pulled open.

[Barry Kirsten]

Thanks everyone for the valuable information.

Steven, I plan a tapered bellows, mainly to minimise size and weight. I want to use this camera mainly with some old brass lenses I have (one of which I bought from you - the Beck RR), and did consider using a Sinar shutter which would require a square bellows, but rejected that idea on the basis of cost.

Steve K, thanks, I hadn't considered the flexibility aspect. I plan all movements for the front standard, but only rise and swing for the back. I don't expect to be using extreme movements though.

Jim and Randy, I'm surprised there isn't more 'clearance' in camera bellows. In all the ones I've seen the rear opening is very close to the long side of the film, and I'd have thought that interference might be a problem, particularly in tapered bellows if there is any sag. The Linhof bellows you describe Randy must be difficult to make. I've seen pictures of that sort of ballooned design but never the actual thing; must indeed be beautiful.

Thanks again.

[SMBooth]

Wont the bellow pleats be determined by the internal frame size and the actual opening all the light goes through?
I don't think you get to determine the pleat width, once you set your inner and outer sizes at both ends and draw it up the pleat widths are set.

[Barry Kirsten]

Hi Shane, to some extent I think you're right. I've seen some descriptions of bellows making that state that, but I'm not so sure. I can't see anything against having frames several mm bigger than the pleat size, to allow fixing screws outside the bellows area, for example. I think the important thing is that the frame edges be *at least* the size of the pleats, or larger.

I should add that we could be talking about two different scenarios here: 1) replacing bellows on existing frames, and 2) making a new camera and bellows from scratch. If the former, I agree, the size of the frames governs all of the measurements of the bellows. In the second case, which applies to me, I think you have room to choose frame sizes and pleat depth

Barry