Canon EOS 550D Instruction Manual page 74

Setting the Image-recording Quality
About
is the raw image data before it is made into d L or other images.
Although _ images require software like Digital Photo Professional
(provided) so they can be displayed on the computer, they also offer flexibility
for image adjustments possible only with _]. _] is effective when you
want to precisely adjust the image yourself or shoot an important subject.
About _÷AL
_]+A L records both a _ and A L image with a single shot. The two
images are saved to the card simultaneously. The two images will be saved
in the same folder with the same file numbers (file extension .JPG for JPEG
and .CR2 for RAW). A L images can be viewed or printed even with a
computer which does not have the camera's provided software.
@_ ÷ JPGI
÷
File numb n
_, 1_+8 L and [9_ Custom Functions (CoFn}] menu's
[High ISO speed noise reduction]
Although the [9": Custom Functions (C,Fn)] menu's [High mSOspeed
noise _eduction] (p.193) settings tStandardtLew/StronglDisable) are
applied to the recorded images, _ne images are displayed without noise
"eduction during image playback (on the LCD monitor and on a TV screen)
or direct printing. (Noise may be noticeable in the images.) You can check
the noise reduction effect or pnnt noise-reduced images with Digital Phe-[o
;rofessional ,provided softwarej
Commercially-available software might not De able to display RAW images.
Using the 1:rowaea software is recommended.
74