III. IMAGEQUALITY SETTINGS 24
RAWvs. JPEG
JPEG Quality
EOS-1 classdigital SLRs allow photographers to shoot RAW files, in-camera JPEGs, or
RAWplus JPEG simultaneously. The RAW file setting records image data directlyfrom the
image sensor atmaximum resolution without JPEG compression artifacts, thus resulting
in maximum image qualityat the expense of relatively large file sizes on the memory
card. In-camera JPEGsare smaller on the memory card and they can be captured at
either fullresolution or various lower resolution settings.
There are severalother important differences between RAW files and in-camera JPEGs.
Imagesoriginally shot as JPEGs are essentially “processed” in the camera as 24-bitcolor
filesaccording to the various camera settings for ISO speed, exposure, white balance,
color space, tone curve, sharpness, contrast, saturation and color tone. With the
exception ofISO speed, virtually all of the other settings listed above, including bit
depth, can be adjusted during post-processing with RAWfiles. RAW files, therefore, offer
far greater flexibilityand produce image quality equal or superior to JPEGs in any
reasonable comparison.
For mostphotographers, the choice between shooting RAW or JPEG lies in the trade-off
between image qualityand convenience. In-camera JPEGs are often completely
sufficientin image quality for a tremendous variety of imaging applications. When the
desired camera settingsare made ahead of time, JPEGs can really speed up your
workflow. However, RAWfiles preserve the highest possible image quality, and they
offer a far greater degree offlexibility in terms of image manipulation.
For those who can’tdecide between RAW and JPEG, or who may need both for their
workflow, Canon EOS-1 classDigital SLRs also feature a RAW+JPEG simultaneous
capture capabilitythat gives you the best of both worlds, JPEGs for immediate use and a
RAWfile for archiving and further manipulation.
JPEG quality, which isCanon’s way of referring to compression settings, can be adjusted
from 1 (maximum compression, minimum image quality) to 10 (minimum compression,
maximum image quality) in 1-step increments. The defaultJPEG quality setting for EOS-1
classdigital SLRs is Level 8. In the case of the original EOS-1D and EOS-1Ds, JPEG
qualityadjustment is programmed in your computer and uploaded to the camera via
dedicated software and the IEEE1394 interface. With the Mark II cameras, JPEG quality
can be adjusted ateach of the 4 different resolution settings on the built-in LCD
monitor.
III. IMAGE QUALITY SETTINGS