Mamiya 645 PRO TL - Manual (Page 18)

Shutter Performance Test
1. Attach the Roll Film Holder to the
camera body.
2. Pull out the Dark Slide and place it
into its Storage Slot.
3. Set the Shutter Speed Dial to any
other position than ‘A”or “AEL”. When
the AE Prism Finder is not mounted
on the camera, the shutter will not
release if the Shutter Speed Dial is in
the “A” or “AEL” position,
the film holder is supplied with a
vinyl tube. When placed in the
take-up compartment it engages
the film sensor and makes the
holder function as if it is loaded
with film. Please remove the tube
4. Set the Multiple Exposure Lever
on the body to the “MULTI” position.