Olympus IS-1 - Manual (Page 11)

*The camera automatically rewinds the film
when you reach the end of the roll.
The final reading on the exposure counter before
rewinding may be more than the number of
exposures specified for the film.
Note: If you want to rewind the film before the end
of the roll, open the mode cover and press the
REWIND button.
Unloading the film
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