Does anyone know the JPG compression ratios for the various recording modes of the Olympus C2000Z? Obviously, the SHQ(1600x1200) mode uses TIFF and is uncompressed? It has HQ(1600x1200 minimal), SQX(1024x768 standard), and SQ(640x480 standard). For example, is the standard compression 1:8 and the minimal compression 1:4? This would be helpful in comparing to other makes and models in quality vs. storage.

-- Brad Grant (grants@mindspring.com), March 30, 1999

Answers

There is an FAQ at photo.askey.net with just this info. The ratios are weird things like 6/1 and 11/1, as I recall.

-- paul wallich (pw@panix.com), April 04, 1999.

SHQ and HQ settings are standard names that Olympus used on the D-500L, D-600L and D-620L (called HQ2 and HQ1 on all of the non-SLRs). SHQ is "ridiculous JPEG compression" (around 99 on the IJG Q scale) resulting in ~1M images at 1280x1024 (so about 1:4 compression) while HQ meant "reasonable JPEG compression" (around 90-95 Q) resulting in ~300k images (or about 1:12). Personally I could never see the SHQ difference, even at extreme magnification, even with highly detailed subjects.

SQ (and presumably SQX) are not only lower resolution but also much more extreme compression (around 40-50 on the Q scale). SQ images from a D-600L are far softer than the equivalent image taken at HQ and reduced manually. That's why I got enough smartmedia to shoot at HQ all the time.

-- Ben Jackson (ben@ben.com), April 11, 1999.