10. Mount the Rollback onto your Mercury camera. Ensure that your lens is in place and your
shutter is closed. You will now expose the film to the inside of your camera, so you will not
be able to change lenses or film backs from this point on without exposing at least one frame
of film. We recommend not removing your lens or back until your entire roll is exposed and
has been removed from the back.
11. Turn the Advance knob (always in the direction indicated: counterclockwise) while watching
the film's backing paper through the red window. You will need sufficient light to see it
clearly. You can use a dim flashlight if you have a hard time seeing the markings on the
backing paper—this is especially recommended when you use the Rollback for the first time.
Advance the knob until you see some markings (usually several circles) which indicate that a
frame number is approaching, then slow down and look for a number “1”. When “1” is
visible in the red window, you are on frame 1. You are now ready to shoot!
1
