6x7 medium-format back on a 4x5 camera

[Jon Warwick]

Apologies if this is the most daft question ever asked, but I am rather new to LF .... assume i have a 4x5 camera + a 110mm lens on its. And I put a 6x7 roll-film holder onto that large format camera.

Am I correct to think the resultant image that i'd record on the film (in terms of what is included from the scene in front of me) would be the same as what I would have recorded if I had used a medium-format 6x7 camera with its 110mm medium-format lens? I can't imagine the answer could be anything apart from yes, but wanted to check!

[David A. Goldfarb]

Yes, 110mm is 110mm on any camera. LF lenses have a larger image circle, so they can cover the larger format, but if you put a smaller format back on an LF camera, it will be just as if you had used a lens of the same focal length on a smaller format camera.

[Jiri Vasina]

Yes

[Jiri Vasina]

using a 6x7cm back is the same as cropping the 4x5" negative in darkroom (to the same size) and it's the same as using 110mm to project the image on any kind of camera (be it MF, 4x5" or anything larger)

[Jon Warwick]

Many thanks for your prompt replies.

Hence .... it seems that -- if I was to use a 60mm lens on a large format camera that is fitted with a 6x7 roll-film back, I would be effectively creating a similar image (in terms of how much of the scene is recorded on the film) to what I could approximately create with a 4x5 sheet film +110mm lens.

If that is the case, is there anything I need to be aware of when using a wide lens (say, 60mm'ish) + roll-film back on a large format camera?? ie, specifically, compared to just using 4x5 sheet film and a 110mm lens, does one end up with less/more flexibility when it comes to "camera movements" if I use a 60mm lens + 6x7 roll-film back on that same large format camera?

[Nick_3536]

Depending on the 4x5 camera you might not be able to use a lens that wide. Even if you can focus it you might find it less then ideal for movements.

[David A. Goldfarb]

It will depend on the bellows and the camera. It might be that the bellows is too compressed with a 60mm lens to leave you any room for movements. If the camera is a folding field camera, it might be hard to access all the controls with a lens that wide. Your best bet for a 60mm lens with a 6x7 back is likely to be a monorail camera with a bag bellows.