View Full Version : Image circle minimum for 5x8

Gary Tarbert
4-Mar-2011, 23:08
Hi Guys, What would be the minimum image circle you would consider usable for mainly landscape ,For the 5x8 format . Cheers Gary

4-Mar-2011, 23:14
The minimum for any format equals the diagonal of the film.

For 5" x 8" that would be sqrt(25+64) = 9.43" = 240mm.

A really useful lens should have an image circle larger than that.

A good table of lens characteristics is available for the Ebony cameras. Google should find it.

- Leigh

Ken Lee
5-Mar-2011, 04:55
A lens whose focal length is the same as the diagonal, we consider a "normal" lens - so a 240mm lens would also give "normal" perspective on 5x8 - like a 150mm lens on 4x5, a 50mm lens on 35mm, etc.