On Tuesday, April 3, 2012, 5:54:16 PM, Elle wrote: > (I wrote): >> Looking at the NEF (raw) file in Nikon Capture NX2 at default settings, I am >> seeing the black patch at rgb 27, 27, 28 and the white at rgb 223, 225, 224. >> (The working RGB space is Beta RGB). So the exposure seems reasonable to me; >> it is the conversion to linear TIFF that is causing the big drop in >> lightness. ES> Linear output looks dark when there is not a proper linear gamma ES> profile embedded, because imaging software assumes sRGB (with sRGB ES> somewhat greater than gamma 2.2 overall gamma) when there is no ES> embedded profile. Yes, I know what gamma correction is ;) (and by the way, I wasn't using sRGB, as noted above. BetaRGB has a 2.2 gamma). So 224 ÷ 255 = 0.878 in gamma 2.2 space with a gamma of 1, that is 0.752 This is substantially different to the 16% (0.16) value for white that Graeme found in the TIFF. Thus, the TIFF was not created correctly. ES> I honestly don't know what Nikon Capture NX2 default settings are, but ES> I rather suspect they cater to NEF files and "by default" do what ES> needs to be done to make the processed raw file look good. Uh, no, not really. My point is that the exposure, as shot, was reasonable. The conversion to a linear space was not correct and has given substantially wrong values. -- Chris Lilley Technical Director, Interaction Domain W3C Graphics Activity Lead, Fonts Activity Lead Co-Chair, W3C Hypertext CG Member, CSS, WebFonts, SVG Working Groups