As camera sensors have changed in size, from model to model, so too must their appropriate focusing screens--and their appropriate crop marks as well. The apertures in the 54 x 40 Focusing Screen for Mamiya / PhaseOne AFD, AF, DF Cameras and an Aptus II 8 Digital Back from Mamiya are different for different digital backs, and each is designed specifically for the given combination of camera and digital back.
The 54 x 40 Focusing Screen is great for accurate composition when using an Aptus II 8 digital back, when combined with a Mamiya / PhaseOne camera. It is useful for general purpose photography, and is designed to fit and function perfectly within this unique system.
Designed to fit 54 x 40 sized Mamiya / PhaseOne AFD, AF, DF cameras and an Aptus II 8 digital back only