Canon MG8100 series On-Screen Manual page 535

check that the film is loaded correctly.
If the holder is not closed flat, press
down across the holder to fit the
protrusions into the slots.
4.
Make sure that the spaces between
frames are aligned with the white
lines on the holder.
Double-check the orientation of the film.
Note
Depending on the film cutting position,
the separation lines between frames
on a film strip may not be aligned with
the white line marks of the Film Holder.
In this case, adjust the location of the
film strip to align the separation lines
between frames with the white line
marks.
5.
Align the tabs on the Film Guide with
the indentations on the left and right
sides of the Platen.
Note
When a film strip shorter than the frame
for film strip is scanned, the image of
the frame next to the area without film
may appear whitish. In that case, cover
the area without film with black paper or
the like.
A sticker label attached to the margin of
the film may be recognized as an
image.
the slides from left to right.
Load the slides so that the film lies flat on the
Platen.
Note
The Film Guide holds up to four mounted
slides at one time.
5. Gently close the Document Cover.