Re: Why is Silverfast better?

[Fletcher Manley <fletch@ncia.net>]

>Unlike many young thinking people today, not everything "old school" is
bad or
>wrong. However, please help me understand what you mean by your
statement,
>while the data is in its analog state". Other than exposure and focus,
how are
>any image elements edited before they are converted to bits? Unless
there are
>some manipulations that I am unaware of (which is entirely possible),
the
>scanner software peforms its operations after the scan. Mind you, it my
seem
>ike tey're being performed during the scan, but what happens is the
scanner
>scans some data, manipulations are performed, then it scans some more,
the new
>data is manipulated, then again, and agian, until the entire frame is
scanned.

Mike -

It sounds to me like the above scan  scenario is referencing a typical
flatbed scanner. Setting up a high end scanner, say the Hell 3000 series
of drum scanners, the image that is taped to the drum, be it transparent
or reflected, is adjusted for hi-light, shadow, mid-tone, quarter-tone,
and three quarter-tone.
Global and selective color  adjustments can be set-up if desired. Under
color removal and
unsharp masking is determined. Scan size,resolution, and of course focus
is set. Most of these adjustments are determined by digital readouts on
the scanner from measurements taken directly off the original image that
is about to be scanned.

When the drum spins the image is scanned by a light beam. The above
setup paramaters are taken into account and measured against the
scanners LUT's. The reflected or transmited light is passed thrrough RGB
filters, broken into components of RGB light energy and amplified
further by being passed  through RGB photomultiplie tubes.

So far the data is still in an analog state and the scanner adjustments
that were set up for that image are being applied in that analog state.
But after the Analog to Digital conversion(after passing through
photomultiplier tubes), then the data becomes digital, of course.

Thus, adjustments, or data manipulation, to the scanned image took place
in an analog state,
before the digital data was passed off to a disk, workstation, or
whatever.

One could simply set hi-light, shadow, and focus at the scanner and send
that raw digital data to the workstation for final image editing. That
is o.k., and can work, but it is not the
best route for optimal results,IMHO.  I have been experimenting with
scanning that way
but passing the raw data through the scanners profile at the work
station,converting to CMYK (in this case I am aiming for a printing
press), and making whatever tweeks I feel
necessary.  I am seeing some advantages to this (primarily the ability
to scan a lot of
material without laboring over individual image set-ups - relying on the
profile to do most of the work), but the one caveat so far is possibly
the black channel. Does the scanner profile
really give me what I want, or amI better of setting that up in the
scanner ? I am just not sure about that yet. For ink on paper via offset
printing the black channel is important.

Anyway, I hope this rather long winded reply helps answer your question.

Fletcher












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