The value for the circle of confusion is a choice made - usually by the manufacturer - which varies according to format size, as the assumption is that larger formats will not be enlarged nearly as much as much smaller formats.
In the 1030's I doubt many folks envisioned 40 x 60 inch prints from a 35mm camera. Most press photographers of that era shot 4x5 Speed Graphics, not even 2 1/4 square cameras. That was one reason why the Leica was so revolutionary - how could anything that small, light, quiet, without a flash take serious pictures?
Comments
In the 1030's I doubt many folks envisioned 40 x 60 inch prints from a 35mm camera. Most press photographers of that era shot 4x5 Speed Graphics, not even 2 1/4 square cameras. That was one reason why the Leica was so revolutionary - how could anything that small, light, quiet, without a flash take serious pictures?
Moderator of the Technique Forum and Finishing School on Dgrin