Mamiya 645 Super Film Back: Repair and Red vs Blue Dark Slides
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Mamiya 645 Super film back repair and differences between the versions. I’m servicing a 645 Super film back damaged from impact. The outer film knob was missing and one of the screws holding it on the camera dropped down inside so a bit of disassembly needed and of course replacing the knob. I am often asked about the difference between the blue dark slide version and the red dark slide version of this back. Well, the original back from 1985 had a red dark slide with a lock button really not visible at the bottom of the back (this keeps the dark slide in the back when not on the camera). With the introduction of the Mamiya 645 Pro around 1993, Mamiya made some changes to the back, the most visible was a dark slide release button on the face of the back that was depressed when the back was installed on the camera body. You can see the button at the bottom right hand corner of the back shown in the photo with the blue dark slide. Yes, Mamiya changed the dark slide from red to blue with the new style back for the 645 Pro produced from date code LH (Aug 1992). These days, the color does not mean much as dark slides have been swapped back and forth on the backs. And the slides are fully interchangeable (the blue color dark slide has a green line running from top to bottom that is visible outside the camera when the slide is pulled far enough out of the film aperture)
