Dear Rishi, > I don't understand how it's not essential to have Dmin & Dmax mapped > to black & white when shooting a target on film. Tone curve can't be properly addressed with a profile, and if you are using a flatbed scanner or modern pseudo-drums, Dmax is a waste because of flare anyway. I shoot film with LF cameras that also flares as hell, so no point in either Dmin or Dmax again. However if you bracket as I explained and make a composite target you will reach both Dmin and Dmax, as it is with my Leica with moderately fast lenses for the scenes that have no more than 9 stops of dynamic range and do not have .very light backgrounds. Profiling from a composite target allows to reach both Dmin and Dmax; but tone curve still needs to be addressed elsewhere as usual. > When building a > 'scanner' profile (not a 'camera' profile), 0,0,0 & 255,255,255 (on an > 8-bit scale) are literally mapped to the darkest and lightest patches > when I use LPROF to build a profile for my Velvia film using Wolf > Faust's 35mm targets (288 patches, IT8 chart). Yes they are, and most often it is done incorrectly. We tried this approach and rejected it because of relatively poor results. It is better to add synthetic patches in a profiler, or manually add them to the target - either by interpolation, or using other considerations. > Are you not building a > 'scanner' profile? Yes, that too. > I know for 'camera' profiles profiling packages > don't require the black on the chart to be 0,0,0 from your camera & > white to be 255,255,255 (in fact, that's really hard to do since > typically your camera has a much wider dynamic range than that > possible from imaging a reflective target) That is why we bracket. > ... because all it's doing > is building a 3x3 matrix, no? Depends. > > For that matter, how does Wolf Faust even create the IT8 targets on > positive film? Using a film recorder, as all such targets are created. -- Iliah Borg ib@xxxxxxxxxxx