On Fri, Dec 09, 2005 at 11:35:38AM -0500, Bob Shell wrote: > > On Dec 9, 2005, at 10:54 AM, [EMAIL PROTECTED] wrote: > > >Thanks Frank. This BW conversion was done by the fast and dirty > >method. Just a PhotoShop convert to grayscale and then some playing > >around with curves until I was happy. > > > It is my contention that converting to B & W that way works just as > well as any of the more complex methods. You just need to understand > how to use curves. > > Bob
Not quite - you lose the ability to change the response based on the hue of the original scene. As an extreme example, consider simulating the effect of an extreme red filter to accentuate clouds. That's easy to do during the conversion, but practically impossible afterwards; once you've mapped two different colours to the same gray value there's nothing you can do to separate them using a curves control. You need three curves, one for each channel, as part of the conversion. If that's what you meant (rather than just one curve post-conversion) then I'd agree with you.
