Olympus E-300 EVOLT Review
Output image file quality / JPEG artifacts
Standard Test Scene
The E-300 has three JPEG presets; SHQ, HQ and SQ. SHQ and HQ are both at full resolution (3264 x 2448), however the HQ setting can be set to either 1/4 or 1/8 JPEG compression. The SQ setting can be any one of six image sizes in combination with either 1/2.7, 1/4 or 1/8 JPEG compression. In addition the E-300 also provides uncompressed TIFF, RAW (Olympus .ORF) and RAW + JPEG (any of SHQ, HQ or SQ).
Below you will find crops of the same 240 x 180 portion of the center of a sequence of images taken at some of the available combinations of image size and quality. Crops shown are at 100%, saved as extremely high quality JPEG. The RAW file was converted to a TIFF using Olympus Master 1.11.
|3264 x 2448 RAW (Uncompressed)
13,797 KB .ORF (not for download)
|3264 x 2448 JPEG SHQ (1/2.7)
5,152 KB .JPG
|3264 x 2448 JPEG HQ (1/4)
3,830 KB .JPG
|3264 x 2448 JPEG HQ (1/8)
1,650 KB .JPG
1600 x 1200 JPEG SQ (1/2.7)
The E-300's SHQ JPEG mode is as good-as-lossless as you're going to get, and the price you pay for that is very large files. My choice would probably be HQ at the 1/4 setting, a sensible image size with almost no visible artifacts. Drop down to the 1/8 setting and you can make out JPEG artifacts around detail. The E-300's downsampling interpolation appears to be very good with clean images and no noticeable jaggies.
The E-300 provides the independent selection of output color space, you can select from sRGB or Adobe RGB. Images taken in the Adobe RGB color space have their filename prefixed with an underscore (_) this complies with DCF 2.0 (Exif 2.21)*. While we're used to seeing some difference in color response between sRGB and Adobe RGB we've not seen something as dramatic as this, Adobe RGB images come out looking far more saturated and indeed can make the standard sRGB balance look a little pale. Place your mouse over the label below the image to see the GretagMacbeth ColorChecker chart taken in each color space.
|sRGB||Adobe RGB (converted to sRGB)|
* This has nothing in particular to do with Olympus 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).
Once again a dramatic difference in saturation between sRGB and Adobe RGB (and the thumbnail below hasn't been converted to sRGB yet, it would be even more saturated). I did for a while wonder if Olympus had mixed up sRGB and Adobe RGB.