I am not a U.S. lawyer; I am a professional commercial photographer by
occupation.
I am neither new to the principles modern color photography nor ignorant of
the history and purposes of the orange mask. I was merely trying to point
out in as inoffensive and rhetorical a way as possible that the set of color
negative films commonly used in contemporary photography are not optimized
for digital uses but for traditional uses. By using a film that is
developed for one usage and optimized to that use for an entirely different
use for which it is not optimized often leads to unintended consequences.
Thus, if you plan to use those films from which to do digital scanning, then
it is important how the mask looks to your eye or the scanner's CCDs and
that the differences are negligible for paper emulsions is irrelevant and
unimportant.
>the negative films were,
>are and will be designed primarily to be copied onto a positive medium, to
>wit a photographic paper.
A bit of an overstatement here. That they were and are designed to be
printed on photographic paper is true enough; but that they have to be in
the future ("will be designed primarily to be copied onto a positive
medium") is not necessarily true. There is no reason why said negative
films could not be designed to be optimized for digital uses only (to wit,
dedicated to scanning) in which case such masks might be unnecessary and
replace by profiles that would digitally account for and correct the
unwanted of a cyan and a magenta dye in the negative film in the same way
that color filter packs are utilized today. As far as I know, there is no
good reason why a film similar to transparency film without any orange masks
could not be produced which would display a negative image rather than a
positive image and would be more appropriate for direct scanning and digital
reversing. Now such a thing may very well be impractical but it is not
impossible or illogical.
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Roman Kielich®
Sent: Monday, January 15, 2001 12:50 AM
To: [EMAIL PROTECTED]
Subject: RE: filmscanners: orange mask
you sound like a first class US lawyer. Indeed, the negative films were,
are and will be designed primarily to be copied onto a positive medium, to
wit a photographic paper.
The reason for the orange mask is an unwanted absorption of a cyan and a
magenta dye in the negative film. It was introduced some 40-50 years ago,
and still provides improved results. Negs are optimised for copying not
watching, not even scanning. Investigate metameric colors, recommend
reading "Digital Color Management" by Giorganni and Madden.
From your response I gather, you are new to principles of modern color
photography.
At 09:42 14/01/2001 -0600, you wrote:
> >Bear in mind that it is not important, how does the mask look to your
eye,
> >but how the paper emulsion sees it. and for the paper the differences may
> >be negligible.
>
>So would one be wrong to interpret what you are saying here in a fashion as
>to infer that it might be generally said that these films with their orange
>masks, whatever the differences, are optimized for traditional photographic
>printing on photographic papers and emulsions using chemical processes
where
>the mask has little bearing on the outcome except maybe to add some time to
>the processing and some contrast to the outcome and may not be optimized
for
>digital scanning and processing where the mask may come into more play as a
>factor in effecting the final printed outcome? Or put another way, the
>differences under the traditional chemical methods are intended to be
>negligible; but not so under digital methods where the scanner can be
>assumed to be like your eye and not like a paper emulsion?
