[argyllcms] Re: help with camera profile
- From: Stephen T <stwebvanuatu@xxxxxxxxxxxx>
- To: "argyllcms@xxxxxxxxxxxxx" <argyllcms@xxxxxxxxxxxxx>
- Date: Fri, 20 Jul 2012 05:30:08 -0700 (PDT)
Colour is critical but most raw photo software developers focus on whimsical
image processing algorithms.
The original colour matrix profiles in dcraw are terrible. Canon's proprietary
output is inaccurate. I have made my own matrix profiles and the results look
better. Now people ask: how did you get the blue sky colour right? With a
simple 3x3 linear matrix transform.
Raw Therapee has some custom DCP profiles that are reasonably good and your
camera might be supported. They are based on the CC24 and seem to behave like
matrix profiles.
Once you have a profile that is conforms to the CIE standard observer, you then
need to sort out your work flow, especially (working space) RGB tone curves
(not available in ufraw). If you want to tweak and enhance the colour further,
that's best done in the RGB working space.
So yes, much of my profiling troubles were due to inadequate software and a
poor work flow!
ST.
________________________________
From: edmund ronald <edmundronald@xxxxxxxxx>
To: argyllcms@xxxxxxxxxxxxx
Sent: Friday, 20 July 2012 7:58 PM
Subject: [argyllcms] Re: help with camera profile
If you *need* camera profiling for a modern camera, there is probably something
wrong with your workflow or with your camera.
My humble suggestion as a practising photographer would be to forget about
"real" camera profiling in anger unless you really MUST do it. MUST means that
you do this professionally for a manufacturer, have an older camera that is
painful to replace, or reproduce artwork, products or fashion.
A need to profiling very often leads to a need for profile editing which opens
another can of worms and necessitates very precisely calibrated screens to be
meaningful.
If you MUST do it, then I would recommend first finding a Raw converter that
plays well with user profiling, eg. some dcraw descendants such as RPP which
has Argyll embedded anyway, the horrid but extremely useful dcraw itself,
Capture One, Adobe Lightroom and Photoshop ACR and of course Iridant's
beautiful mac-only Raw Developer.
Chances are you will find decent canned profiles for your camera for all of the
above. However if your light is exceptionally strange or you camera is whacked,
there is a small cheap object made by Xrite called a Colorchecker Passport
which is a target especially designed for carrying around for profiling on
location. The advantage of this is it that it is designed to be carried around
photographed by normal unskilled human beings (I helped specify it to that
end), and also very useful for visual assessment of the results.
And, although you will find me patronizing, all of you being technically gifted
high IQ individuals, I do reiterate that the need for camera profiling and in
particular the apparent inadequacy of a simple matrix profile are usually signs
of bad workflow or extreme expectations.
Edmund
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