Output image file quality / JPEG artifacts

Standard Test Scene

The Digilux 2 provides five select image sizes from 2560 x 1920 down to 640 x 480. It also unusually includes a HDTV standard size of 1920 x 1080 which crops the top and bottom of the frame. You can combine any of these sizes with three levels of JPEG compression (we have called these Super-Fine, Fine and Normal although the Digilux 2 manual refers to them as Very Low, Low and Normal compression rates). Additionally of course the Digilux 2 also provides a RAW mode which outputs one RAW file and one Fine quality JPEG for each shot taken.

RAW conversion note: The Digilux 2 is supplied with Silverfast DC SE for Leica, I found its RAW conversion to be very disappointing and therefore chose to use Adobe Photoshop CS with the latest Camera RAW plug-in the crop shown below is from a TIFF output from Photoshop CS.

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.

2560 x 1920 RAW (converted in Photoshop CS)
9,672 .RAW + 1,158 KB .JPG (not for download)
2560 x 1920 JPEG Super Fine
3,774 KB (1:1 compression, 8 bpp)
2560 x 1920 JPEG Fine
2,214 KB (2:1 compression, 4 bpp)
2560 x 1920 JPEG Standard
1,142 KB (4:1 compression, 2 bpp)
2048 x 1536 JPEG Super Fine
2,447 KB (1:1 compression, 8 bpp)
1600 x 1200 JPEG Super Fine
1,356 KB (1:1 compression, 8 bpp)
1280 x 960 JPEG Super Fine
1,008 KB (1:1 compression, 8 bpp)
640 x 480 JPEG Super Fine
310 KB (1:1 compression, 8 bpp)

The Super-Fine (Very Low compression) JPEG setting is the lowest compression JPEG we've seen from any digital camera, it results in extremely large file sizes with absolutely no JPEG artifacts (you'd have a hard time distinguishing it from TIFF). The next compression level down will probably the one most used, still low compression with almost no JPEG artifacts but weighing in at around 2 MB per image.