Digital BW, The Print

Ernst writes:

> If we are on that route I suggest to get a
> scanner for B&W film that is a true B&W scanner
> as well.

It shouldn't matter for scanners, since they are scanning material that
transmits all wavelengths of visible light equally.  However, a B&W scanner
might be very slightly better, all else being equal.  It would be faster,
too.

> If it was true that a mosaic CCD or three
> line sensor can only contribute 1/3 of its
> quality for a B&W image this difference
> wouldn't be so significant.

It's true for mosaic CCDs, but scanners don't use mosaics.  They scan all
three colors for every pixel.

> It just isn't so simple that a mosaic CCD or
> CMOS can only contribute 1/3 of its data to
> B&W.

You're confusing the original capture of the image from real life with
subsequent transformations.  It's the ORIGINAL capture that counts (I guess
I should have been clearer about that).  You don't lose anything with a RGB
scan of B&W film.

> The best process for art reproduction/archiving
> these days is done with multi spectral takes
> where up to 7 narrow band filtered CCD images
> are used for the final image. I'm sure one could brew
> a nice B&W image of that colour image if needed, most likely a
> much better one than if only one is done without
> a filter.

Sort of.  Having seven color values lets you grayscale with much more
flexibility than having three color values does.  However, direct B&W
capture records _all_ colors, not just three or seven, and so it works
better than anything else for B&W.