LStar
LStar
- Subject: LStar
- From: "Mark Rice" <email@hidden>
- Date: Tue, 17 May 2005 18:56:21 -0400
LStar is not really a gamma but a gray scale constructed so that each step
VISUALLY appears to be an even increase in brightness from the step before
it. This is why it is sometimes referred to as the "Equal brightness" scale.
The first time I saw it used was on the LVT film recorder as calibration
material - it was valuable, because all the steps didn't disappear in the
shadows or highlights, as they often do with gamma. You could visually see
all the steps down to 3.4 DMax and up to .08 DMin
Mark Rice
email@hidden www.zero1inc.com
I tried LStar "gamma" many times. LStar seems to be intermediate between 1.8
and 2.2 -- or was it even darker than 2.2? I can't remember well because
it's been a while since I used it. Currently, I use a plain 2.2 gamma and I
can't complain. But I'd really like to know more, technically, about LStar.
> Carlo
>
> PS
>
> It also seems to me that basICColor softly suggest that a Luminance set to
> maximum it's also advisable or is it just my poor English?
Yes, that's the suggestion. But that does not seem very 'bright', IMO. I
know I always specify a target luminance of around 90 cd/m2, given the
ambient level I work under.
Regards,
Roger Breton | Laval, Canada | email@hidden
http://pages.infinit.net/graxx
------------------------------
Message: 5
Date: Mon, 16 May 2005 20:46:54 -0400
From: "email@hidden" <email@hidden>
Subject: Re: Eizo Calibration/basICColor with GAMMA L*
To: email@hidden, email@hidden,
email@hidden
Message-ID: <email@hidden>
Content-Type: text/plain; charset=iso-8859-1
The folks at Color Solutions Software not only offer L* contrast in their
display software, but also a
new working space with L* uniformity in the gray balance.
While I have not fully translated the white paper from German, it seems
that with access to the
native Eizo internal calibration LUTs as well as access to the video card
LUTs, basICColor display is
able to find an optimized contrast which produces the best perceptual
gradation.
This may vary somewhat with native whitepoint, monitor technology, and
other factors.
My starting point is usually:
Measured Whitepoint
L* contrast
150 cd/m2 for photographers
100 cd/m2 for printers
Hope this helps.
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