Image Size / File Quality Options

The EOS-10D provides seven different image size / quality combinations. You can choose from image sizes of 3072 x 2048 (Large), 2048 x 1360 (Medium) or 1536 x 1024 (Small) in combination with either Fine JPEG or Normal JPEG quality settings. In addition there is of course RAW image format, this contains a RAW 'dump' of the data directly from the sensor (12-bits per pixel), a RAW file can not be viewed natively and but must first be converted. Most people consider the RAW format to be the 'digital negative' because it is lossless and has had no image processing applied to it (white balance, sharpening etc.) all of which can be adjusted at a later date before outputting the final image.

Standard Test Scene

To give an impression of what some of the combinations of image size and quality produce the table below is a cross reference of some of them:

• 3024 x 2048 RAW (to TIFF using Canon File Viewer 1.2.1.16)
  
• 3024 x 2048 JPEG Fine
• 3024 x 2048 JPEG Normal
• 2048 x 1360 JPEG Fine
• 1536 x 1024 JPEG Fine

Crops below are of the same 240 x 120 area of each image nearest neighbour magnified 200%.

Settings: ISO 200, Parameters: Normal, EF 28-70 mm F2.8L @ F10

	3024 x 2048
RAW	As a 4,825 KB JPEG or original 6,535 KB .CRW & .THM (Canon RAW)
JPEG FINE	2,651 KB
JPEG NORM	1,325 KB
	2048 x 1360
JPEG FINE	1,360 KB
	1536 x 1024
JPEG FINE	840 KB

If you look very closely at the edge of the black arc on the watch surface you can see that the RAW image is cleaner, the JPEG exhibiting some slight artifacts. JPEG Fine would seem to be the best compromise between size and quality, JPEG Normal delivering more artifacts.

Obviously having all those additional pixels at your disposal means that smaller size images either straight out of the camera (Medium / Small sizes) or 'down sampling' Large images at a later date produces very sharp and very clean images. This is one of the big advantages of having such a large (pixel count) image.

Adobe RGB

The EOS-10D now provides support for the Adobe RGB color space. Adobe RGB has the advantage of providing a wider color gamut than sRGB, for all colors but more so for greens (as can be seen in the CIE XYZ chromaticity diagram below - the entire gamut of color visible to the human eye).

Adobe RGB is accessed by selecting the parameter set 'Adobe RGB', once selected however it is not possible to make any individual parameter adjustments (such as tone, sharpness, contrast, saturation). This is a fairly severe limitation, especially if you want sharp-out-of-the-camera Adobe RGB images. Canon really should have provided control over the Adobe RGB parameter 'Set'.

Note that the color of the Adobe RGB sample below will look dull on your sRGB monitor, you will need to load it into a color space smart application such as Adobe Photoshop and assign the 'Adobe RGB' profile.

Settings: ISO 200, EF 28-70 mm F2.8L @ F14, Small/Fine

Standard (sRGB)	Adobe RGB