Digital BW, The Print

> on 10/28/01 1:37 AM, Cleavis wrote:
>
> > BACK TO THE QUESTION given this 'info'...When I bring something into
> > photoshop 5.2 IT won't let me utilize most of the controls other than
> > levels in 16 bit mode...so if you must immediately convert to 8-bit
> > to manipulate why bother scanning higher??? Especially if chances are
> > 256 greys are going to do it any way since the printer range is maxed
> > out?
>
> Cleavis,
>
> The deal is this, and I'm gonna be brief (Austin jump in when I
> get it wrong
> ;-). Scanners really only scan one way, and that is raw. They read your
> analog data and convert it/write it out as linear digital code.
> This results
> in a raw file, which when you see it as an image, it's dark and tonally
> compressed (flat). To adjust it from this raw state requires software
> manipulation of the data/image. This happens after the raw data has been
> written. Your scanner's software (through it's driver settings)
> can do this
> for you somewhat behind the scenes, and when your image opens from the
> scanner it will already be adjusted.

That is pretty much correct.  Some scanners have LUTs (Look Up Tables) that
get "loaded" with your "curves", and these curves get applied to the raw
data in the hardware before the data is sent back to the computer.

One of the things is the newer PCs are just so damn fast, that really not
much has to be done in the scanner any more...and the setpoints and tonal
curves can easily be done "on the fly" by the scanner software on your
computer.

The main reason for "using" high bit data is specifically for tonal
adjustments and setpoints.   Other than that, I don't see any large
advantage to using high bit data...but I don't apply any of the PS filters
at all, so I really couldn't say if it would be better done in high bit or
not.

Personally, I just get my tonal curves and setpoints perfect in my scanner
software, so I only use 8 bit data in PS anyway...but that is mostly because
my scanner software has good setpoint and curve tools (as well as a built-in
histogram ;-).