Output image file quality / JPEG artifacts


Standard Test Scene
The DSC-R1 provides only two JPEG image quality levels of Fine and Standard. These can be combined with any of the five output image sizes; 10M (3888 x 2592), 7M (3264 x 2176), 5M (2748 x 1856), 3M (2160 x 1440) or 1M (1280 x 864). In addition you can also select 'RAW' mode which outputs a Sony format RAW file in addition to the selected JPEG format (so is effectively a RAW+JPEG mode). One thing we found pretty disappointing is the inefficient format of the DSC-R1's RAW files, they weigh in at 20,534 KB each, clearly Sony is recording 16-bits for each photosite (wasting 4-bits per photosite) and is not employing any kind of lossless compression.

Below you will find 200% magnified crops of the same 240 x 100 portion of the center of a sequence of images taken at full size but different output settings. The RAW file was converted to a TIFF using Sony Image Data Converter SR 1.0.

3888 x 2592 RAW (Uncompressed) - 20,534 KB .SRF (not for download) (VGA TIFF crop)
3888 x 2592 JPEG Fine - 4,142 KB .JPG
3888 x 2592 JPEG Standard - 2,295 KB .JPG

As we've seen on previous Olympus cameras the SHQ JPEG is as good as lossless and makes the TIFF option pretty redundant (you'll be hard pushed to see a difference). The optimum mode is probably HQ at the 1/4 setting which delivers files of around 4 MB with virtually not artifacts at all. Higher compression than this (1/8 or 1/12 settings) do lead to some JPEG artifacts, especially around detail edges.

Color mode / color space

The DSC-R1 has one menu option labelled 'Color', this allows you to select between Standard (which is in sRGB), Vivid (also sRGB) and Adobe RGB color output modes. As you can see from the samples below the 'Standard' mode is already pretty vivid, saturated enough for my tastes, selecting the Vivid option turns color saturation up even higher and also increases image contrast. In Adobe RGB mode color saturation is slightly higher, contrast slightly lower.

Images taken in the Adobe RGB color space have their filename prefixed with an underscore (_) this complies with DCF 2.0 (Exif 2.21)*. Place your mouse over the label to see a ColorChecker chart shot in the respective mode.

Standard (sRGB) Vivid (sRGB) Adobe RGB

* This has nothing in particular to do with Sony but this renaming system makes it difficult to keep your images in the correct order if you don't routinely rename them by date/time.

Color space: CIE u'v' Color Distribution chart

Note that in these samples 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. Below each sample is the 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).

Standard (sRGB) Vivid (sRGB) Adobe RGB