Remember that in doing RAW conversion you are performing a gamma correction on a linear dataset. This means compressing (pushing closer together, setting the white point on...) the high values) while expanding (stretching apart, setting the black point on...) the low values to fit the range of what you've captured to the characteristic curve of human vision. You also set the gamma and inflection point of the curve (brightness and contrast).
While both ends of the spectrum lose some data in the course of doing this, there is far more data to work with at the high end of the scale than at the low end of the scale if you've made a correct exposure for the linear gamma sensitivity curve of a digital sensor. Setting the black point too early can throw away an excess of data, for which there is no recovery post RAW conversion. For this reason it is suggested that you set white point, then gamma and inflection, and then very carefully black point. While the three are *mostly* independent of ordering, and "whatever works well" is indeed best, I find it better to work in this order and iterate through the settings a couple of times in small moves rather than make large adjustments all at once. You can always adjust the black point further in RGB space using curves or levels adjustments, I generally prefer to preserve a little excess data in the dark regions and make the final adjustments there. Godfrey On Jan 7, 2007, at 4:54 AM, Paul Stenquist wrote: > I sometimes set the black point first as well. I'm not really > conscious > of a specific ordering of steps in regard to exposure, brightness and > shadows. I think I vary my sequence in respect to the specific > needs of > the shot I'm working with. > Paul > On Jan 7, 2007, at 7:03 AM, Jan van Wijk wrote: > >> I agree with Tim on this one. >> >> Otherwise, I must say Paul's description is >> pretty close to what I usually do :-) >> >> I have developed my RAW workflow based on CS1 experience >> and Bruce Frasers "Real World Camera Raw ..." book. >> >> Working with CS2/Bridge now, and will consider LightRoom >> once it it released, or perhaps CS3 ... >> >>> >>> But unlike you, I think it is better setting the darks before >>> brightness. If >>> I set darkness before brightness, it seems I always need to go back >>> again. >>> -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
