Re: Media Testing for maclife.de
Re: Media Testing for maclife.de
- Subject: Re: Media Testing for maclife.de
- From: MARK SEGAL <email@hidden>
- Date: Wed, 10 Sep 2008 06:53:11 -0700 (PDT)
Ken,
What you say in #2 below is probably a correct statement of intent, but also a problemmatic one, because something that pleases some people will displease others and something that looks pleasant in one kind of image may well look unpleasant in others; I don't think there can be such a thing as a raw converter that can be all things to all people and all situations, and that's why the most important characteristic of a raw converter needs to be its flexibility and adaptability - and where I think Adobe wins hands-down.. Then there are those applications of photography I mentioned yesterday where perceptual colour accuracy really is the objective, not "pleasing" colours. In these latter situations it is reasonable to want a profiling solution "out-of-the-box" which comes as close as possible to "accurate colour rendition", but how close is possible I don't know, becaue one would need very considerable expertise on sensor response, the Bayer matrix and
its demosaicing, etc. which I don't have; I assume the Adobe folks developing these products have studied this in depth and they do know, but of course this statement doesn't prove anything - it's just an expression of a reasonable expectation of the highly competent professionals they are, for what it's worth. Those of us who aren't experts on the guts of all the relevant technological factors and processes must depend on these people, and on others who are trying to test various solutions empirically for outcomes, even if they may not have a detailed knowledge of all the inner workings.
I don't find Adobe's raw settings "out-of-the-box" all that pleasing for many of the photos I make, but here one needs to distinguish between what the profile is doing and what the default settings are doing - for example, the default contrast setting of +25 assigned the 1DsMk3 tends to smother deep shadow detail which exists in the raw data for scenes with extremes of contrast where even good "Expose to the Right" technique is not fail-safe. But there is a workable solution to this: create a default with everything set to zero and the tone curve linear, then build the image till it is "pleasing" , which has a number of subjective attributes including shadow detail, avoidance of signficant highlight clipping, attractive but realistic contrast, saturation and clarity, and a colour balance which reflects the photographers' intent viz a viz the character of the scene's predominant hue(s). Because LR/ACR allows me to do this very successfully most of
the time, I have to conclude that the profile of my 1Ds3 working under the hood is an important feature of this "enabling environment". Because LR and ACR now have such incredibly effective and intuitively easy tools for achieving one's objectives, along with seamless integration into Photoshop for more advanced work when required, regardless of all the discussion about profile "accuracy", the Adobe products are the ones I shall continue to use until I'm convinced there is something superior on the market, and that hasn't happened yet. But I'm not into forensic, medical, scientific or product photography.
In testing various profiling solutions for "accuracy" I remain concerned about fundamental issues such as the definition of what it really means in operationally signifcant terms and the adequacy and reliability of the testing procedures deployed relative to the unverse of photographic scenery. Uli may well be making a useful contribution to an understanding of these issues, but that can be better assessed by those with the technical competence to do so once his material becomes available in full.
Mark
----- Original Message ----
From: "Fleisher, Ken" <email@hidden>
To: Uli Zappe <email@hidden>
Cc: ColorSync Mailing <email@hidden>
Sent: Wednesday, September 10, 2008 7:46:46 AM
Subject: Re: Media Testing for maclife.de
Uli,
I think you are confused by what is being described to you. A single ICC
profile cannot account for multiple lighting conditions. In other words, if
a scene has more than one illuminant "simultaneously" lighting the scene in
varying amounts. What you describe, and tested, are multiple illuminants as
single sources in the scene (not simultaneous). This is not the same thing.
Another observation is that you are working on the assumption that a raw
converter's default settings are the manufacturer's best attempt at the
optimal settings. This an incorrect assumption for at least two reasons.
1) A raw converter must be capable of interpreting images from many
different situations. There simply is no "best" setting. The default
settings are generally just null values for each of the options (or
sometimes a general guess like a sharpening setting). This in no way implies
the appropriateness of the settings for any particular image. For the
"camera" profiles described that try to imitate the "look" of a particular
camera, it is a little more accurate to assume the settings have meaning,
but that meaning is in no way to imply number 2 (below).
2) The goal of all raw interpreters is to make pleasing images, not color
accurate ones. Therefore, even if the default settings were meant to create
the manufacturer's best attempt at the "correct" settings, the target of
these settings is a pleasing image, not a color accurate one (as Chris Cox
said about the Adobe products). So whether the CC24 patches hit their
targets or not is irrelevant.
Keep in mind that I am in favor of ICC profiles for camera profiling and
camera profiling is something that I work with daily. I too would like to
see the "option" of using the ICC route in a camera raw workflow. I merely
wanted to point out what I see as 1) a misunderstanding in language and 2) a
flaw in your premise from your experiments.
Ken
On 9/10/08 12:10 AM, "Uli Zappe" <email@hidden> wrote:
>> A single ICC profile cannot account for multiple lighting conditions
>> - that is one of the big, well known, well understood limitations of
>> ICC profiles.
>
> And wrong, as my measurements revealed (in the meaning I explained
> above).
>
> Of course, this result is remarkable, but the numbers are clear: my
> best ICC profile was better in *any single* lighting condition than
> e.g. Adobe's default profiles. See my upcoming report, where I will
> publish the numbers.
--
Ken Fleisher
Photographer
Imaging & Visual Services
National Gallery of Art
Washington, D.C.
Phone: (202) 712-7471
email@hidden
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