[filmscanners] RE: 8 bit versus 16

["LAURIE SOLOMON" <laurie@advancenet.net>]

-----Original Message-----
From: filmscanners_owner@halftone.co.uk
[mailto:filmscanners_owner@halftone.co.uk]On Behalf Of Austin Franklin
Sent: Wednesday, September 17, 2003 9:12 PM
To: laurie@advancenet.net
Subject: [filmscanners] RE: 8 bit versus 16


Laurie,

>> At the risk of raising Austin's ire,

>Au contraire!  You hit the nail on the head ;-)

Gee, that is good I hope. :-)


>> I think that he is being more of a
>> purist than most people in both what he regards as the proper workflow
and
>> the correct way to use scanners to capture images off of film or flat
>> artwork and prints.  ....

>Exactly!

Magnificient; but here comes the other shoe.

>> While I do see some technical disagreements in
>> the discussion as to possible benefits and uses of 16-bit scans
>> (raw lineal
>> or raw non-lineal scans) and the potential benefits and uses of
>> enhancement
>> and adjustment tools the support working with 16-bit files,

>But...here's the rub.  If you get the setpoints and tonal corrections
>reasonably close in the scanner driver, keep in mind, this is all done
using
>high bit data...  it's just how scanners work...it completely moots the
>discussion of 16 vs 8 bit files...as there would be no need to do large
>tonal moves post scanning.

The other shoe?

First, it assumes that the software being used allows for this; but granting
that it does for purposes of argument, it may completely moot the discussion
for you but not for others for a number of reasons that they are trying to
tell you but while you are listening you are not hearing. Among those is the
fact that since as you say if you get the setpoints and tonal corrections
reasonably close to the scanner driver using high bit, you have done
essentially what they say they are doing just they have choose to do the
setpoint correction and tonal adjustments to the high bit data in a third
party editor rather than in the scanner even if it is possible with the
scanner software that they are using since they feel more compfortable with
the third party image editor or it is better than that of the scanner
software.  I think they all recognize that to apply some Photoshop plugins
and features or even to print they need to convert the file to 24 bit in
order to do so and that that should take place after the tonal corrections
and setpoionts have been established.  There is also the fact that, while
one can establish set points and tonal curves that match the optimum
hardware capabilities of the given scanner and that these can remain
constant, for most of us, the subject matter being scanned does not remain
constant and may require modification of the set points and tonal curves
from scan to scan or so and is dependent on the original being scanned
rather than the devices capabilities per se.  Such modifications may best be
done after the scan in an image editor where one can actually preview the
consequences of proposed adjustments on the fly in real time as they are
being done.  In that case the establishment of setpoints and tonal curves
for the scan should be taken as merely a preliminary raw approximation
rather than the final product with the main tonal moves being done post
scanning.

Second, it very well can be the case that one does not wish to replicate the
exact setpoints and tonal curve of the original that was scanned but to
deliberately alter or modify the tonal character of the scanned result for
artisitic or other reasons; there would be every reason for doing major
tonal moves post scanning.

>> As for persons claiming that certain technical scanning problems
>> are either produced because scans were 8 bit rather than 16 bit or can
best be deal
>> with if the file is 16 bit versus 8 bit, I think that this is essentially
an
>> empirical and practical question (even if theoretically and
>> analytically a case could be made for said claims).  Thus, Austin's
request for concrete
>> examples is legitimate and justified with respect to such claims.

>And, interestingly enough, no one can come up with any images that
>demonstrate this.

>> That they
>> have not been produced does not indicate as he would have it that they do
>> not exist or are not significant; but it does serves as grounds for his
>> refusal to accept said claims as well as legitimate grounds for his not
>> wanting to partake in the discussion...

>Hey, did I say that? ;-)

Maybe not; but it was implied even if you did not think you said or implied
it.  It is that implication that I think is responsible for raising the
hackels of some of those with whom you are locked in this inane debate with.


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