histograms in Capture and Nikon Scan

[ted_norris]

What is the difference between the "RGB" histogram under the Curves menu, and the "Master Lightness"

histogram under the LCH menu ?

Sometimes, the two histograms appear quite the same for an image, but sometimes remarkably

different (both in Nikon Scan and Capture).

The follow-on question is, what are you doing differently when you adjust curves using one vs the

other ? I read somewhere someone's opinion that using the LCH master lightness was better, but I don't

know what the basis for that statement was.