Canon EOS 1D - Manual (Page 50)

50
Before You Start
If the card is new or was previously formatted by another camera or
personal computer, formatting the card with the camera is recommended.
When the card is formatted, all images and data in the card will
be erased. Even protected images will be erased, so make
sure there is nothing you need to keep. If necessary, transfer
the images to a personal computer, etc., before formatting the
card.
1
Select [Format].
Under the [5] tab, select [Format],
then press <0>.
2
Select the card.
[f] is the CF card, and [g] is the SD
card.
Turn the <5> dial to select the card,
then press <0>.
3
Select [OK].
When [g] is selected, low-level
formatting is possible (p.51).
Turn the <5> dial to select [OK],
then press <0>.
X The card will be formatted.
X When the formatting is completed,
the menu will reappear.
3 Formatting the Card
COP
Y