8x10" at which length, is an auxiliary bellows support necessary?

[John Layton]

I like Bob's idea of the paper cup...except I'd add a wee dram (or two) of bourbon to this - for a bit of extra "support!"

[John Kasaian]

I like Bob's idea of the paper cup...except I'd add a wee dram (or two) of bourbon to this - for a bit of extra "support!"

An excellent idea!

[Tin Can]

Buy the long bellows

Study this free aid

https://dofsimulator.net/en/

[Drew Wiley]

The other simple trick is to attach a velcro tab outside the bellows, topside and midpoint. Then use a long strip of the opposite Velcro attached to the rear standard to tension it. But I've never found the need to resort to any of these tricks when just a 600mm focal length lens was involved.

[John Layton]

Actually, depending upon the bellows design/materials/max. extended length...the problem with sag can tend to occur not at longer extensions...but at medium extensions, especially after changing lenses from those that require near-maximum extensions to those that require medium extensions - as the stretching out tends to create a bit of "memory" in the pleats. Not a problem with shorter extensions as the pleats are mushed closer together and tend to support each other as a unit.

Also keep in mind that bellows sag tends to be more of a problem when composing vertically - as the top edge of the frame is closer to the edge of the field.

[Bernice Loui]

The original 5x7 Sinar Norma tapered bellows had internal elastic strips that would support the bellows and worked good to prevent bellows sag as the tapered bellows was extended. Good and very functional design made of high quality leather.

Later Sinar 5x7 tapered bellows is made of what appears to be a stiffer synthetic material that does not sag as the bellows is extended. This bellows will expand to about ~20 inches or ~510mm, more camera/bellows extension can be easily added.

Bernice