[argyllcms] Re: help with camera profile

  • From: Alberto Ferrante <alberto.ferrante@xxxxxxxxxx>
  • To: "argyllcms@xxxxxxxxxxxxx" <argyllcms@xxxxxxxxxxxxx>
  • Date: Mon, 23 Jul 2012 00:17:37 +0200

I thank you all for the replies and suggestions. I will try to look at
them in the next days (sorry, but I have been busy taking pictures in
the last days ;-)).

Some replies to different posts are below.

> Yellow cast might be the result of wrong setting of the clipping in the 
> converter as Nikolay suggested. 

I don't think this is the problem. I checked saturation with dcraw and
the value set in the dcraw code is lower than the one of my camera.
Furthermore, I tried playing with the ufraw (dcraw) matrix profile and I
discovered that, by lowering linearity (I was using 0.10, I am now using
0.05), the yellow cast, that was also there, almost disappears.

> RawDigger is designed to run under Wine. Ir will alos allow you to check the 
> saturation level for sensors.

Thanks, I will check that!

> My matrix-based 5D3 profiles are OK. I can confirm that some few tints of 
> yellow do have wrong renditions due to the filters used in the camera, but 
> those are in a very narrow range of Lab. LUT profiles attempting to 
> accommodate 
> for these variations usually make things worse sacrificing profile smoothness.

I will try with a different target as soon as I can get one.
I tried removing some patches from the ti3 file (one or two yellow ones
that had high errors) and this slightly improved things.

> As Edmund said, you can try also taking a profile from CaptureOne, those are 
> LUT-based.

I will also check this!

> 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.

RawTherapee is a great tool, but the last time I tried it, a couple of
months ago, it had too many bugs. I tested photivo and, despite being a
bit complex (too many options, probably), I like it... The only problem
is that it uses an old release of dcraw where the Canon 5D III is not
supported... I will wait for a newer release.

> If you *need* camera profiling for a modern camera, there is probably
> something wrong with your workflow or with your camera.

Edmund, I think Stephen already gave a reply to this: unfortunately,
many great raw conversion pieces of software miss a good color profile.
I am now playing with ufraw (dcraw) matrix profile and I have to admit
that the one for the 5D III does not look so bad if properly tuned.


Home page: http://www.alari.ch/people/alberto
Photo galleries : http://albertoferrante.name
Public key: http://www.alari.ch/people/alberto/keys/yahoo.asc

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