On 2009-10-01, John Mills <johnmills@xxxxxxxxxxxxx> wrote: >> With cameras which use more advanced versions of the Apical Iridex >> hardware or firmware (starting with Sony, but Nikon is reported to be >> in process of catching up), the situation is not as clear. I did not >> see any report of RAW processor which can match Apical-style "Dynamic >> Range Optimizations". > >> So: there might be one respect (tonal mapping, sometimes called >> "dynamic range") in which RAW-processed-JPEG might be not as good as >> in-camera one... > I'm not sure I follow that, unless the sensor's bit-depth and that of the > camera's RAW format are different. Sensor bit-depth is an absolutely bogus metric (unless one uses it as "an indicator of amount of R&D", which may correlate with other, important issues; such as read noise and correlation of noise of nearby pixels). If RAW files were compressed to 8-bit gamma=2, they won't loose "practically any" information; 9-bit would be a significant overkill (assuming full-well about 70K electrons, as typical large-sensor dSLRs have). gamma=2.2 is very similar. (The special significance of quantization after gamma=2 is that Poisson noise becomes "constant-width", thus dithers in dark parts as well as in highlights.) If you do not know what DRO is, look on dpreview, and/or look for examples on Apical site. Ilya _______________________________________________ Gimp-user@xxxxxxxxxxxxxxxxxxxxxx https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user