Canon Pixma MP800R User Manual page 72

Mounting 35 mm Slides:
(1) Align the film guide with the indentations on the right and left sides of the Platen Glass.
(2) Mount the slides in the film guide with the front side (the side showing the correct image)
face down and with the image upside down. Load the slides in the landscape orientation,
making sure they are not loose in the film guide.
Important
The images may be unsatisfactory if the film is set beyond the reference position (A) indicated
by the white line. Do not set the film beyond the reference position.
70 Photo Printing from Photo or Film
(A)
Chapter 4