Canon EOS 20D Instruction Manual page 112

Erasing Images
You can erase images individually or erase all the images at one time in
the CF card. Only protected images will not be erased.
_4_ Once an image is erased, it cannot be recovered. Make sure
you no longer need the image before erasing it.To prevent
important images from being erased accidentally, protect
them.
Erasing a Single Image
_'_I Display the image,
_ Press the <r_q> button.
'_jj,,, Select the image to be erased.
_ Turn the <O> dial to select the
image to be erased.
_ Display the erase menu.
_ Press the <_> button.
#_ The Erase menu will appear at the
bottom of the screen.
_ Erase the image.
_ Turn the <_> dial to select [Erase],
then press <_>.
#_ The access lamp will blink and the
image will be erased.
_ If there are other images you want to
select, repeat steps 2 to 4.
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