Colour space

While reviewing the DiMAGE 7 I soon discovered that it was in fact recording images in a proprietary (custom) colour space. The same was true of the S304 and also the S404. To get the optimum colour balance (and accuracy) it is necessary to run images through the supplied DiMAGE Image Viewer Utility with the 'colour space correction' option selected and sRGB (that used on your computer monitor) or whichever colour space you work in selected as the output colour space.

Most digital cameras are 'set up' (I would like to say calibrated, but hardly any are) to give the best results on sRGB output devices (such as your computer monitor) we will be using sRGB for our output colour space in this review, this will also ensure the optimum colour viewing the images in your web browser.

The samples below of a GretagMacbeth ColorChecker Chart were taken in normal daylight with manual white balance taken from a grey card. Roll your mouse over the image to see the differences between the colour balance straight from the camera and that of an image which has been re-saved into the sRGB colour space (the same as your monitor).

(Roll your mouse over image to see sRGB image)

In general it seems to be worth converting from the original "Minolta" colour space to sRGB, certainly if you are at all concerned about colour matching. It's true however that some people prefer the look of the colours straight out of the camera, you have that option. You can download the same image below, also re-saved into the sRGB colour space and Adobe RGB colour space.

Native DiMAGE S404 image	Converted to sRGB	Converted to Adobe RGB

There are positive and negative aspects to the S404's proprietary colour space. There is good because it means that the S404 is capable of capturung a wider colour gamut (depth and range of colours) than other consumer level digital cameras (and produces more accurate colour overall). The downside must be that to appreciate the camera's full colour capability you need to either convert them to a standard colour space (and view them correctly in that colour space). Lastly we never recommend people open and re-save JPEG's time after time (it introduces unwanted artifacts), this additional step will of course have a slight effect on image quality.

Minolta really should have given the user the option to select output colour space in camera, a simple Colourspace: Minolta / sRGB option in the SETUP menu would have been sufficient.

I won't repeat myself too much, you can read about this discovery and a more detailed explanation about colour space in our DiMAGE 7 review. Click here for a description of the Image Viewer Utility.

Important review notes

From this point onwards in the review if you see the following text: "Image re-saved to sRGB colour space" you will know that the images / crops of images you are viewing have been run through the Minolta Image Viewer application. Note that NO adjustments other than the colour space conversion are made. I noticed no difference in detail (resolution) between the native and converted images. The Minolta Image Viewer appears to maintain EXIF information.

JPEG/TIFF Image Size & Quality

Standard Test Scene

The DiMAGE S404 offers a wide variety of resolution and image format options. You can choose from JPEG (three compression levels) or TIFF. In combination with a resolution of 2272 x 1704 (native CCD), 1600 x 1200, 1280 x 960 or 640 x 480. The S404 does not have the RAW mode seen in the DiMAGE 5 and 7.

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:

• 2272 x 1704 TIFF ("Super Fine")
• 2272 x 1704 JPEG FINE
• 2272 x 1704 JPEG STANDARD
• 2272 x 1704 JPEG ECONOMY
• 1600 x 1200 JPEG FINE
• 1280 x 960 JPEG FINE
• 640 x 480 JPEG FINE

Images below are cropped 240 x 100 area of the image magnified 200% (nearest neighbour).

	2272 x 1704
TIFF	11,400 KB (Not available for download)
JPEG FINE	1,538 KB
JPEG STD.	787 KB
JPEG ECON.	541 KB
	1600 x 1200
JPEG FINE	957 KB
	1280 x 960
JPEG FINE	680 KB
	640 x 480
JPEG FINE	250 KB

Note that because we're looking here at the quality of the S404's JPEG/TIFF encoder none of these images have been run through the Minolta Image Viewer. Overall JPEG FINE very clean being almost identical to TIFF. JPEG artifacts creep in at the STANDARD compression and are clearly visible in ECONOMY mode.