[scribus] How to use color management?

[Hal V. Engel]

On Saturday 30 August 2008 05:04:05 pm dwain wrote:
> hal,
> thank you for the very eye opening reply.  i have never heard it put
> so clearly and authoritatively.  you make me want to go out and buy a
> measuring device and really get my color management act together.
>
> yes i have a system that works for me and has for several years now,
> even with commercial printers.  you really can't knock that aspect.

On the other hand I think you will be pleasantly surprised at what happens to 
your monitor once it has been calibrated and profiled with a measurement 
device.  Back when the hardware was expensive and unsupported on *nix systems 
I used to do things sort of like what you are currently doing.  Mostly because 
even if I spent the $500 or so that it would have cost for measurement 
hardware and calibration/profiling software I still couldn't use it since the 
software wouldn't run on my machine.  In other words I did it out of 
nessesity.   For *nix users because of the efforts of the open source 
community (Graeme Gill in particuar) this is no longer an issue.

What I am getting at is that the change from an uncalibrated monitor (or one 
"calibrated" by eye) using guestimate profiles to an environment with 
measurement based calibration and measurement based custom profiles was a 
significant and very noticable improvement for me and this will likely the 
case for you.  I have also done monitor calibrations and profiling for other 
people using my hardware and in every case the user was very surprised at how 
much difference it made.

Another area of "improvement" will be in your confidence level in how well 
your work flow is working since you will now have at least one part of the 
tool chain that you know with a high degree of confidence is actually very 
close to correct.  Because of this you wil likely discover other aspects of 
your work flow that can be improved (IE. the results from my ABC scanner do 
not look correct on my calibrated and profiled monitor maybe I should create a 
custom profile for it?  My room lighting is too bright and too warm...). 

Since I now work on software that uses these devices I have a small collection 
of measurement devices that I use for testing and I use a few of these to 
handle my own calibration and profiling tasks.  Of my monitor only devices I 
like my X-Rite EyeOne Display Lt  the best (this is the same hardware as the 
Display 2 but the software bundled has some features removed).  It is more 
expensive than a Huey but the Windows software that comes with the EyeOne 
Display Lt (or Display 2) is significantly better than the software that comes 
with the Huey.   The Huey software bundle is very easy to use but it is also 
brain dead and crippled.  For those willing to work with open source software 
the differences are much smaller on the software side (the Huey does not have 
a true ambient light measurement mode since it does not give a color 
temperature reading) and I find that the Huey is a very good device although 
it is not as good at the dark end of the tonal scale as the i1d2 class devices 
but better in this regard than the Spyder2.  By the way stay away from the 
Spyder devices since the vendor is openly hostile to the open source 
community.  When I help others with calibration/profiling I normally use the 
Huey since it is very small and easy to transport but also because it is a HID 
device which makes installation easier on Windows machines since no drivers 
are required (this avoids issues with driver signing).

Also keep in mind that CM involves things like room lighting and lighting for 
print viewing.  Even if you have everything else correctly setup if your room 
lighting and or print viewing lighting is not correctly done you may not get 
good monitor to print matching since the lighting affects the print and also 
how your vision works.  The opposite is also true in that both your monitor 
setup and lighting could be way off and if they are both off in the right 
directions you could end up with what appears to be good monitor to print 
matching even in cases where the print would not match if the lighting and 
monitor were setup correctly.  So you also need to pay attension to viewing 
conditions and your lighting setup.  Use D50 bulbs with high CRI ratings (at 
least 85 but the closer to 100 the better - ISO calls for 90 or higher).  The 
light level in your work room should be at most 64 lux and it is better to be 
32 lux or lower (this will seem dim to dark to most users).  The light level 
in your print viewing booth should result in a white level that is a close 
match to your monitor. 

Your work room should be neutral and you should wear neutral clothing when 
doing color critical work.  People who are really into CM will actually paint 
thier work room gray and will select paint for the room using a 
spectrophotometer and sample swatches from the paint vendor to make sure the 
room is really neutral.  They will also wear black clothing when doing color 
critical work and will furnish the work room with gray and black furnishings.   
There is actually an ISO standard for the above (including lighting) if you 
want to look it up and there are web pages that cover it in some detail and 
that include specific paint recommendations for those that don't have a 
spectrophotometer; please see http://www.creativepro.com/article/the-darkroom-
makes-a-comeback and http://www.creativepro.com/article/the-darkroom-makes-a-
comeback-part-2- .   For many users this last part may be a bit over the top 
but the previous paragraph about lighting requirements is critical.

>
> on a different note; what happens when you change commercial printers?
>  do your profiles go out the window?  i know not for your particular
> setup, but what about the transfer of files.  different printer,
> hardware and software for the commercial printer; how does one handle
> the color management then?  do commercial printers who have a goodly
> amount of color management knowledge tinker with you file or do they
> set your file to their color profile and everything is hunky-dorry?  i
> have always wonder about this.

Assuming the printing service is actually CM savey this is a non issue.  They 
know how thier printers work and have custom profiles for them and have thier 
RIP setup to handle converting your files to the correct color space for thier 
printers as long as you have your files properly taged with profiles.  Which 
it appears you are currently doing.

Hal
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