Digital BW, The Print

Martin writes:

> I have seen far too many fine B&W prints made
> from scans of color transparencies to agree
> with you on that one!

You can certainly get good B&W from color transparencies, but you can get
only ONE B&W that way.  I meant good in the sense of B&W as produced by true
B&W films.  You cannot duplicate the results of actual B&W films by
grayscaling RGB images.  You can get one type of B&W from RGB, with a couple
of minor variations, but you can't get the vast majority of B&W renderings
offered by dedicated B&W capture (film or digital).

The classic example is infrared (because that's easier for people to
understand), but it applies to B&W in the visible light range, too.

> My remarks were actually a question as to whether
> color digital cameras that are a match for 35mm
> color film and transparencies would match 35mm B&W.

Only to the extent that color film and transparencies are a match for 35mm
B&W.  The constraints are identical for both color digital and color film.