The ‘120’ medium roll film format goes back to 1901, and was introduced by Kodak as an amateur format, specifically for the Brownie No.2. It was eventually adopted widely by professionals when film, camera and lens quality improved. The film is nominally 60mm wide (but actually closer to 61mm!) and the number on frames on the film depended on the camera or film back used and ranges from 3 to 16 per roll.
The format we use in our film recorders is known as ‘6×7’ and gives 10 frames per roll. The actual imaged area is approximately 67.8mm x 55.5mm and will show your entire image if supplied at 8192 x 6702px.
6×6 and 645 formats.
If you supply square images then this will produce 6×6 negatives. Optimum image size is 6702 x 6702px and the actual negative image area will be approx. 55.5 x 55.5mm.
If you require 645 negatives then they will produce negatives approximately 55.5 x 41.1mm. The optimal digital image size is 6702 x 4967px.
6×7, 6×6 and 645 negatives are all the same price.