Previous page Next page

Output image file quality / JPEG artifacts


Standard Test Scene
The D50 provides three different output image size options; 3008 x 2000, 2256 x 1496 and 1504 x 1000. These can be selected in combination with three JPEG quality levels. In addition of course the D50 also provides a RAW capture mode which is written into Nikon's compressed NEF file format. There is one RAW+JPEG mode which captures a single RAW file as well as a Basic quality JPEG.

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 very high quality JPEG using PictureProject 1.5.2 (which has no TIFF output option).

3008 x 2000 RAW (saved as 3,512 KB JPEG)
5,378 KB .NEF (not for download)
3008 x 2000 (L) JPEG Fine
2,504 KB .JPG
3008 x 2000 (L) JPEG Standard
1,328 KB .JPG
3008 x 2000 (L) JPEG Basic
741 KB .JPG
2256 x 1496 (M) JPEG Fine
1,576 KB .JPG
1504 x 1000 (S) JPEG Fine
900 KB .JPG

The D50's JPEG Fine setting delivers very clean images with no visible JPEG artifacts, Standard is also fairly good, you'd have to look very closely to see anything. The Basic setting is obviously a storage space compromise and it shows, fairly clear 'mosquito artifacts' around areas of detail. At the smaller image sizes the D50's downsampling interpolation is very good, nice clean aliasing with no noticeable jaggies.

Color modes / color space

Just like previous Nikon Dxx digital SLR's the D50 provides three color modes, mode Ia and IIIa are both mapped to the sRGB color space. In a change from the D70/D70s the D50's default color mode is mode IIIa which delivers punchier more saturated color with a stronger response to blues and greens (good for sunny outdoor shots). Mode II is in the Adobe RGB color space, in this case image filenames prefixed with an underscore (_) this complies with DCF 2.0 (Exif 2.21)*. Place your mouse over the label below the image to see the GretagMacbeth ColorChecker chart taken in each color space.

IIIa (sRGB) (default) II (Adobe RGB) Ia (sRGB)

* This has nothing in particular to do with Nikon 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).

IIIa (sRGB) (default) II (Adobe RGB) Ia (sRGB)
Previous page Next page
160
I own it
2
I want it
194
I had it
Discuss in the forums

Comments