Image Size / File Quality Options

The EOS 300D 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 (tone, 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 1.3.1)
  
• 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 100 area of each image nearest neighbour magnified 200%.

Settings: ISO 200, Parameters: Parameter 1, EF-S 18-55 mm @ F10

	3024 x 2048
RAW	Original 7,841 KB .CRW & .THM (Canon RAW)
JPEG FINE	3,477 KB
JPEG NORM	1,798 KB
	2048 x 1360
JPEG FINE	1,989 KB
	1536 x 1024
JPEG FINE	1,385 KB

As we have come to expect a straight conversion of the RAW file is virtually indistinguishable from Canon's high quality full resolution JPEG Fine. It's clear from this that Canon have tweaked their JPEG compression to be less aggressive (file sizes are larger). To my eye there are no JPEG artifacts in Fine mode and only a few very slight visible in Normal mode.

Canon use a very good quality interpolation algorithm when downsampling to smaller image sizes (probably bilinear or even bicubic) this provides extremely sharp and clean low resolution detail.

Default Image Parameter Sets

The EOS 300D is tweaked to be 'punchier' out of the box than the EOS 10D (in Canon's words to deliver "images ready to print"). To achieve this Canon has replaced the EOS 10D's single "Standard" Parameter with two labelled "Parameter 1" and "Parameter 2" (not very descriptive). Parameter 1 sets Saturation, Contrast and Sharpness to +1, this produces a more contrasty image with stronger color and slightly sharper detail. Parameter 2 is completely neutral (it's the same as the EOS 10D's "Standard").

Interestingly Canon kept Adobe RGB, an option I would have expected them to drop on an 'entry level' digital SLR, but perhaps the support for Adobe RGB seen on some of the high end prosumer cameras has forced Canon's hand on this.

Settings: ISO 100, EF-S 18-55 mm, 1/80 sec, F8

Parameter 1	Parameter 2	Adobe RGB -> sRGB

Place your mouse over the labels below the image to see a ColorChecker chart taken in each default parameter setting. Note that the Adobe RGB image has been converted to the sRGB color space. Below are three shots, each taken in a different parameter mode. Note that in this example the Adobe RGB image has NOT been converted to sRGB and so to view it correctly you will have to load it into a color space aware photo application and assign the Adobe RGB color space.

Dynamic range note: The use of Parameter 1 while delivering more contrasty images does appear to sacrifice dynamic range (sometimes clipping highlights earlier). I personally would probably use Parameter 2 most of the time, however we will use Parameter 1 for the majority of our gallery shots as this is how Canon intended the images to look 'out of the box'.

Below are three sample images taken in each of the default parameter sets, below each sample is that image's CIE u'v' Color Distribution chart; larger gray triangle approximately represents the range of color which the human eye can resolve, the inner triangle the available gamut in each color space (sRGB or Adobe RGB).

Settings: ISO 100, EF-S 18-55 mm @ F13 (Studio Strobe), Medium/Fine

Parameter 1 (sRGB)	Parameter 2 (sRGB)	Adobe RGB