Re: filmscanners: Sharpening scanned images for printing

[SKID Photography <skid@bway.net>]

Todd Flashner wrote:

> To Austin:
>
> I think Harvey's point is that there may come a situation where someone
> wants a sharp scan of a blurry image. Why not, it's art! ;-)

What I was trying to say was that a scan of a negative (let's say B&W) *is* a 
scan of its grain.  If the
scanner can't get the grain sharply rendered then it can't make a sharp scan.

I don't car if you have the world's on the world's best tripod on the world's 
sharpest film.  If the scanner
canter render the *film* sharply, it can't make a sharp scan.  The holga was 
used as an an example of where
one wants to look at the film itself and not necessarily of the image on hat 
film.   Obviously, it went over
Austin's head, or he ignored the concept.

>
>
> Austin wrote:
> > 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.
>
> I think on one level there can be no doubt a CCD film scanner (don't know
> enough about drum scanners to say) will loose sharpness, color or BW. It has
> to, it's an analog generational loss. Light passes through film and gets
> scattered, it then passes through a lens which possibly introduces flare,
> diffraction, and aberration, then it hits the CCD which is prone to blur,
> smear, and blooming, and finally the electronics introduce noise. It's
> analog, the question can really only be "how much" is lost, not "if".

Actually I was referringto drum scans (which tend to be inherrently sharper 
then ccd scans), so the ccd red
herring is of no concern to me.

>
> The whole question about sharpness occurs to me as "how sharp is sharp"? Is
> a file the right degree of sharpness when a print from it is as sharp as a
> traditional darkroom print? Is that a contact print or an enlarged print?
> Cold light head or point source? Should the image at 100% magnification on
> screen look as sharp as the film through a 100x microscope? Or, is the right
> sharpness as sharp as one can make it in Photoshop before offensive
> artifacting occurs? Even if that makes it appear sharper than the original?
> On screen or in print? What output: film recorder, offset press, or Epson?
> If the output process softens an image is it fair to oversharpen in in
> anticipation?
>
> These are rhetorical questions which I pose purely to establish that
> sharpening is a choice, a variable, not a rule.
>
> To Harvey, who wrote:
>
> >> Then why do (real) hi bit scans require less sharpening than low
> >> bit scans?
>
> Harvey is it possible that by and large (certainly more so in the past than
> today) the higher bit scanners have been the higher quality scanners? I mean
> highbit used to come at a steep price, and from quality components. Still
> does for "real" bit depth as you put it, by which I think you mean extended
> dynamic range.

The scanners I was referring to are the very top end drum scanners (in the 
$100,000 range). The true 48 bit
scanners vs. the true 36 bit are supposed to need less sharpening.  Pure and 
simple.  Go to NancyScans and
talk with them.  Yes the 48 bit scanners are newer, but I think it's more of a 
software change than the
hardware breakthrough.

>
>
> To Austin who wrote:
> <snip>
>
> > 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.
>
> True.

While I agree with that, and while I think most people over sharpen, my 
statement (on the conceptual level)
still stands:
Higher bit depth scans need less inherent sharpening than lower bit depth scans 
and the sharpness of a scan
has *nothing* to do with the sharpness of the original image.  It's about 
rendering the film emulsion
regardless of what's on it) as crisply as possible in a digital file.

>
>
> > Most people don't sharpen grain, they sharpen the image.

And that image was originally made up of the aforementioned grain.

Harvey Ferdschneider
partner, SKID Photography, NYC