Pentax Optio 50L User Manual page 22

The SD Memory Card has a limited service life. If it is not used for a long time, the data on the card may
become unreadable. Be sure to make a backup of important data on a PC.
Avoid using or storing the card where it may be exposed to static electricity or electrical interference.
Avoid using or storing the card in direct sunlight or where it may be exposed to rapid changes in
temperature or to condensation.
When using an SD Memory Card with a slow recording speed, recording may stop while you are taking
movies even when there is adequate space in the memory, or shooting and playback may take a long
time.
For information on compatible memory cards, contact your nearest PENTAX customer service center.
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