What film format do you use?

I always use Mamiya 7 cameras which produce 7 x 6 cm negatives on 120 roll film.

In the past I used Mamiya 6 cameras for 13 years for 6 x 6 cm negatives, a Mamiya 645 Super camera for 7 years before this (6 x 4.5 cm negatives). I also used 35mm Nikon cameras for 15 years before switching to medium format Mamiya cameras in 1986.