Loupe magnification for focus calibration

[lrochfort]

Hello all,

My father-in-law got me a travelwide 4x5 camera for my birthday.

The instruction leaflet says to use a loupe when calibrating focus for your lens on the focusing screen.

Could you please suggest what magnification to get? Would the same magnification level be suitable for viewing medium format and 4x5 negatives?

Many thanks.

 

[oftheherd]

Three, five, and ten power are the most common I have seen. Five is probably the highest you would want, and thee should be OK.

 

[graywolf]

Usually recommended for focusing on the ground glass is a good quality 4x loupe. Too strong and you are looking at the ground glass grain instead of the image.

A 4x loupe on a 4x5 gives you about the equivalent of a 16x20 print viewed from a couple of inches away.

 

[sevo]

I have a 4x Schneider and a 7x Horseman - I mostly use the latter for focusing, but that is positively too much for viewing film (unless I want to inspect the film for flaws).