Re: filmscanners: Why not sRGB ?

["Steve Greenbank" <steve@gccl.fsbusiness.co.uk>]

So what's the colour gamut of the average human eye and how much variance is
there between people's perception ?

I bizarrely found during the colour blind discussion that I could change the
hue of some of the colour charts such that I (CB) could very clearly see the
correct number on the chart and so called "normal" people could see nothing
but dots.

It rather makes me wonder if we are metaphorically chasing the Holy Grail. I
use AdobeRGB and feel I get quite a good match on the 1270 with Epson papers
when printing from PS. I can also get prerceptually decent results from my
digicam with slightly different driver settings without the colour matching.
I have however sometimes seen posturisation on digicam pictures from the
Epson that have been converted to AdobeRGB before editting and subsequent
printing.

It all seems to be a bit of a mess. We have one set of colours for each of
the following:

1) scanner
2) monitor
3) printer
4) human eye -  which is uncalibrated and has wild variations from one too
another.

None of them match up - each has some colours that are not seen by other
devices/people. We then have an artificial mediator in the middle (the
processing colour space eg Adobe RGB) which also has colours that are not
seen by any of the other 4 and the 4) also have colours that can not be
represented by the processing colour space. We then do 8 bit conversions
(theres bound to be some inaccuracy here) from one colour space to another
where neither can represent the other in it's entirety.

Perhaps we should be amazed that we ever get a good match.

Steve
----- Original Message -----
From: "Maris V. Lidaka, Sr." <mlidaka@ameritech.net>
To: <filmscanners@halftone.co.uk>
Sent: Sunday, August 12, 2001 10:34 PM
Subject: Re: filmscanners: Why not sRGB ?


> Laurie,
>
> Are you sure about that?
>
> I don't know, but I suspect that the 4-color general/business application
> inkjets also print colors outside of the sRGB color space, primarily
> because, in general, some ink colors are outside of the colors visible on
> the monitor just as some colors visible on the monitor are not printable
> using normal printing processes, i.e. inkjets.
>
> Maris
>
> ----- Original Message -----
> From: "LAURIE SOLOMON" <LAURIE@advancenet.net>
> To: <filmscanners@halftone.co.uk>
> Sent: Sunday, August 12, 2001 12:49 PM
> Subject: RE: filmscanners: Why not sRGB ?
>
>
> | shAf,
> | What the original poster fails to take into account and you failed to
> point
> | out is that not all Epson inkjet printer are the same just as not all HP
> | inkjets are the same.  Some are 4 color general/business application
> | printers while others are photo application printers (4 or 6 color).
They
> | do not all have the same color gamut.  The lower end general /business
> color
> | printers probably do not need a larger gamut than sRBG; whereas the
higher
> | end photo printers may produce much higher quality outputs with the
larger
> | color gamut.  Obviously one can print on any color inkjet with the
> narrower
> | sRBG gamut; and in that sense it is suitable for all inkjets; however
that
> | does not make it optimum for all inkjets. :-)
> |
> | -----Original Message-----
> | From: owner-filmscanners@halftone.co.uk
> | [mailto:owner-filmscanners@halftone.co.uk]On Behalf Of shAf
> | Sent: Sunday, August 12, 2001 7:27 AM
> | To: filmscanners@halftone.co.uk
> | Subject: RE: filmscanners: Why not sRGB ?
> |
> |
> | Steve writes ...
> |
> | > Many people on this list use Epson printers that supposedly
> | > work with sRGB.
> | > If you don't use external printing services or if the
> | > external service you use have their printing set-up to
> | > sRGB then why not use sRGB.
> | > Everytime you convert to or from one colour profile to
> | > another you have the potential to mess up your print
> | > If your end target is sRGB (which includes web work) why
> | > not just work in sRGB?
> |
> |     If you have absolutely no need for a color space with a larger gamut
> | than sRGB, then you may as well be using it ... archive to target.  But
I
> | believe you're wrong about sRGB being the suitable color space for Epson
> | printers, and sRGB certainly does not contain some colors available to
> print
> | with Epsons ... even AdobeRGB doesn't.
> |
> |     You are correct in saying there is a "potential" for messing up your
> | print with color space conversions, but it isn't necessarily the case
...
> | you simply need to know what you are doing within a chosen workflow.
(...
> | granted, it sometimes isn't so simple ...)
> |
> | shAf  :o)
> |
> |
>
>