Canon EOS-1DX Instruction Manual page 124

Setting the Image-Recording Quality
Using the Menu Screen to Set the Image Size
With [Standard / Auto switch
card / Rec. to multiple] set:
With [Rec. separately] set:
124
1
Select [Img type/size].
Under the [z2] tab, select [Img
type/size], then press <0>.
2
Set the image size.
To select a RAW image size, turn the
<6> dial. To select a JPEG image
size, turn the <5> dial.
On the screen, the "***M
(megapixels) **** x ****" number
indicates the recorded pixel count,
and [****] is the number of possible
shots (displayed up to 9999).
Press <0> to set it.
Under [51: Record func+card/
folder sel.], if [Record func.] is set to
[Rec. separately], turn the <5> dial
to select <f> or <g>, then press
<0>.
On the screen that appears, turn the
<5> dial to select the image size,
then press <0>.