----- Original Message -----
From: Ezio <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, January 12, 2001 5:26 PM
Subject: Re: filmscanners: Fw: Color Profiles for Printers was scanners
> Pete, I am not an expert ,
me neither.
>but as far as I have understood the matter
> regarding the colors space is directly affecting the printing process and
> its rendering of colors.
> IMHO the screens cannot reproduce anything wider (certain blue, certain
> green and so on) than sRGB gamut. It is something relatd to phosphores and
> the 3 colors added each other with certain intensity.
> For RGB printers (and more for other color rendering technologies) this
> limitation is not any more valid.
> What I have understood , please correct me if I am wrong or saying
no-sense,
> is :
> RGB printers 3, 5 , any number of inks ... can combine the colors in a way
> that is not achievable (by some extension) by the phosphores of the
screen.
> As a consequence we have :
> looking to any picture represented by a physically limited device like the
> screen ... no matter wich color gamut we have encoded because it may fall
> outside the numerical domain representable by the screen itself ... but
when
> looking to a printed output then the difference is there because the
> printers can reproduce / make some of those colors outside the domain of
> ''screen reproduceable'' colors even if they likely cannot reproduce all
the
> possible colors, their domains depending from their own/peculiar
technology
> and its implementation.
>
> Then ... you say:
> > AFAIK, any translation from one colour space to another can only throw
> away
> > colour information, not add it.
>
> This is what I should like to understand better ...
> So ... if I have understood ... I start with a wide gamut = input to PS
from
> scanner
Does any scanner really output a gamut wider than sRGB? ( exclude high end
PMT Drum scanners)
> 1... I convert to sRGB = I HAVE LOST INFORMATION
Not if you didn't start with anything greater.
> 2... I convert to a different wide gamut = I loose information , but this
is
> affecting ''less'' my results provided that the gamut of arrival is
defined
> for a domain ''compatible'' with the capabilities of my printer.
Huh? The difference in printed gamuts to an inkjet (or any reflective) is
probally less than we can detect.
> 3... I convert from sRGB to a wider gamut ... how can I add informations
if
> the information are not there ? ... is this process of passing from a
> ''narrow'' gamut to a ''wide'' gamut doing something similar to the
> interpolation used when passing from a resolution to a higher resolution ?
Does a wider gamut reflect higher resolution or even more information?
There is a difference between outputing to a profile and outputing a wider
gamut.
Does a wider gamut result in a bigger file? I don't see an increase in
Photoshop.
The best I can see, is that a wider gamut maps the bits to a greater range
(ie.stretchs the bit range). Use Profile to Profile or Convert Profile
(Photoshop 6) and the file size does not change.
>
> Sincerely.
>
> Ezio
>
> www.lucenti.com e-photography site
>
>
> ----- Original Message -----
> From: "photoscientia" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Saturday, January 13, 2001 12:27 AM
> Subject: Re: filmscanners: Fw: Color Profiles for Printers was scanners
>
>
> > Hi Shaf
> >
> > shAf wrote:
> >
> > > > The only time you need or can use Wide Gamut RGB is if you
> > > > are going to output your digital files back to neg or
> > > > transparency.
> > > > ...
> > >
> > > Somewhat correct ... but you're ignoring archiving all the RGB
> data,
> > > and the usefulness of highbit editting before you convert to a color
> > > space which is more appropriate for hardcopy.
> >
> > Say what?
> > I still don't see how any colour detail is gained from a so called
> wide-gamut
> > space.
> >
> > As I see it:
> > The scanner outputs numbers between 0 and 255, or 0 and 4095.
> > The scanner hardware knows sod all about colour spaces, and the computer
> doesn't
> > care either.
> > The image file might as well be a recipe for chicken soup as far as the
> hardware
> > is concerned.
> > Those numbers only become meaningful as images when they're converted to
> > voltages that pull electrons from the colour guns of my monitor, and
> that's the
> > only colour space that's visible to me, or meaningful to me when I'm
> editing an
> > image. I call this colour space "my monitors gamut colour space", but
> > unfortunately that profile isn't listed by Photoshop, the nearest it
gets
> to it
> > is sRGB.
> >
> > Please explain how calling that colour space another name can add any
more
> > saturation, brightness, or subtlety to the colour represented by those
> numbers.
> > I'm not trying to pick an argument here, just looking for a clear
> explanation,
> > preferably in engineering terms, not pre-press jargon.
> > I understand Munsell charts, tristimulus values, colour temperature and
> white
> > points, but I'm afraid I cannot follow the logic of working in notional
> colour
> > spaces at all.
> > AFAIK, any translation from one colour space to another can only throw
> away
> > colour information, not add it.
> >
> > Regards, Pete.
> >
> >
> >
>
>
