Well, there are other formats on 120 film. 2-1/4 X 2-1/4 is
only one. At one time the most popular was probably 2-1/4 x
3-1/4, 8 images on a roll, the standard for many box cameras.
There are at least four formats on 120 film (not counting
panoramic cameras).
Most enlarging lenses for 6cm x 6 cm (easier to type than
2-1/4 x 2-1/4) are 80mm but some are 75mm. 75mm gives you
slightly larger images but 80mm has slightly better illumination
uniformity and is somewhat easier to correct. If you have a long
column a longer lens can give better illumination.
Rodenstock (and maybe Schneider too) recommend lenses with
the best correction for a given range of magnification. If you
follow this you will probably use lenses of conventional focal
length. I have not found it makes much difference but it might if
you are doing the most critical work.
I think this is making something complicated that should be
simple. If one gets into the arcane detail of optics its like
swimming in molasses.
On 7/16/2018 2:46 PM, Robert Marvin wrote:
"6X6' and "120" and don't forget 2 1/4 X 2 1/4 :-)
