RE: filmscanners: Sharpening scanned images for printing

["Austin Franklin" <darkroom@ix.netcom.com>]

Harvey,

> So, I still maintain, that in *this* discussion, the sharpness of
> the original has no bearing on the need to
> sharpen scans for printing.

For YOUR purposes, if you want to shoot a Holga and scan grain, that's
fine...but most people 1) don't do that and 2) don't do that...so how is
that relevant?

> whereas sharpening a scan for offset (or whatever kind of
> reproduction) is a technique used to properly
> express what is actually on the original film and to overcome an
> inherent flaw of scanning technology.

You must be referring to color.  I only talk about B&W, and there is no
"inherent flaw" in scanning B&W, if you do not scan B&W in RGB.  The
"inherent flaw" you speak of is simply bloom and smear, which isn't really a
"flaw" but a characteristic of how CCDs respond to different wavelengths of
light.

> >
> > > And aren't higher bit level scans sharper than lower bit
> > > ones?....
> >
> > No.  In fact, they would be softer, since there are more tonal levels.
> > Sharpness is really nothing but contrast, as in difference in
> tonal values.
>
> Then why do (real) hi bit scans require less sharpening than low
> bit scans?

I don't know (nor do I believe at this point in time, at least for B&W) that
they do.  Perhaps you can explain why you believe they do.  For B&W, it is
entirely counterintuitive that they would.  Clearly, a pure monotone image
has the highest level of sharpness one can have, and adding more tones, just
makes things less sharp.  Perhaps you can email two images to me that show
that high bit images require less sharpening, or post them on the web?

I don't believe many people can tell the difference between an image printed
using 8 bits (providing the data occupies all 8 bit values) and one printed
using a higher bit output...so how on earth can you tell that one does or
doesn't require more or less sharpening?

What I have said is that people who sharpen might want to look at the rest
of the process to find the source of why they sharpen...if the image is
fuzzy on the film, it'll be fuzzy on the scan.  Not the grain, but the
image.  Most people don't sharpen grain, they sharpen the image.

Regards,

Austin