[argyllcms] Re: New to color management
- From: "Hal V. Engel" <hvengel@xxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Thu, 24 Jan 2008 11:17:57 -0800
On Thursday 24 January 2008 10:18:27 Leonard Evens wrote:
snip
> I use Vuescan (www.harmick.com) under Linux with my Epson scanner. You
> can use the argyll programs to create a scanner profile, but I found
> that the built-in Vuescan procedures for building profiles worked well.
> That required IT8 targets which I got from www.targets.coloraid.de I
> made a scanner profile using the scanner IT8 target, and I also
> photographed the camera IT8 target using color negative film and use the
> Vuescan procedure for profiling film. That is not supposed to work, but
> it appears that it did. If you go this route, there are some confusing
> aspects, so let me know and I may be able to save you some time.
The last time I checked VueScan only generated and supported the use of
matrix/shaper profiles. XSane now supports the use of any type of profile
including LUT profiles.
>
> > I have no idea (yet) how important ambient light is, and how to
> > compensate for it. The primary PC is relatively far away from any direct
> > outside light, and there is always artificial light in that room. The
> > other PC's are more exposed. One is a laptop, and moves, so it will be
> > hard to compensate for ambient light all of the time for it.
It matters a lot. Get one of the recommended books as these all have a
section on lighting.
snip
> Just what gimp does with color management is still something of a
> mystery. I haven't been able to find any good advice about it anywhere.
> The gimp documentation is not too helpful. I can share some of my hard
> won insights, and I would be happy to learn anything that you've managed
> to figure out.
Current versions of GIMP only supports a color managed display and it only
supports a single monitor profile so you need to be careful on multi-monitor
setups.
For color managed printing on Linux check out PhotoPrint or use CinePaint.
snip
> I tried it with my scanner, but it didn't work very well. I was at an
> early stage in the learning process, so perhaps I might do better now.
> If you can afford it, I strongly recommend a measuring instrument such
> as the Eye One Pro.
I have not tried this with ArgyllCMS but I have used ProfilePrism which is
specifically for this type of setup. I found that this is very tricky to
setup and at best the results were OK if everything is perfect and much worse
if not. It might be better than not having a profile if you happen to have a
setup that works OK but in the vast majority of cases you will get much
better results using a spectrophotometer or a reflective color meter for
measuring your printer targets. To be clear I was never happy with the
results I got using ProfilePrism with my printer/scanner and I even purchased
a scanner specifically recommenced by the author of ProfilePrism.
If you want to have custom profiles for your printer then either get a
spectrophotometer which is expensive or go to a vendor that creates custom
profiles and have them make the profiles for you. I know there is someone on
this list that does this for a very reasonable fee. In the end this will
likely be way less costly than buying a spectrophotometer. The Epson ink jet
printers should only need one profile per paper for the life of the printer
assuming you are using Espon inks.
>
> > > > * Is there a lot of difference in profiling quality between the
> > > > different spectrometers ? I mean, given that all of them would be
> > > > used with Argyll CMS, would one spectrometer result in a better (more
> > > > acurate) color profile than another ?
> > >
> > > Someone else may answer this.
For quality devices in good condition there is almost no difference.
> > >
> > > > * If that is the case, what can you recommend ? What's your
> > > > experience with different spectrometers ?
> > > > * Reading through the Argyll CMS documentation, I read that I would
> > > > require some test charts to profile printers and scanners. Are such
> > > > test charts provided with the spectrometers or do I have to buy them
> > > > separatly ? If so, where could I buy these ?
> > >
> > > The short answer are, it is possible to create printer charts with
> > > argyllcms. You need a spectrometer or a scanner to "read" the chart.
Also to profile scanners and cameras you need a target like an IT8.7 target.
> >
> > Ok, thanks.
> >
> > > I think the odds are close to zero for using the spyder3 with
> > > argyllcms. The spyder2 should work fine but you have use firmware
> > > stripped from a dll file. Normally people on this list recommend the
> > > eye-one display 2 or the cheaper huey, because of the firmware
> > > workaround. All this devices are colorimeters. If you are looking for
> > > a spectrophotometer look for a package called eye-one photo LT.
> >
> > I suppose you mean that the firmware workaround required for the spyder2
> > makes it less recommended than the eye-one display or the huey ?
It is more that that. The company that makes the Spyder devices has a very
bad attitude toward the open source community. Much worse than X-Rite and
X-Rite could stand some improvements in this area. So the Spyder devices
should be avoided on principle as well.
Hal
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