Re: New Colorchecker
Re: New Colorchecker
- Subject: Re: New Colorchecker
- From: <email@hidden>
- Date: Sat, 29 Oct 2005 17:07:39 -0400
Edmund,
Have a look at it another way:
Your old chart's red is 1 DeltaE (D50, CIE94) (or 3.25
DeltaE CIELAB) from the average I computed so far (on the
pdf I sent you), with the main difference being the chroma
(Delta_C* = +3.1)and hue (Delta_h* = -0.9).
Your new chart's red is 1.7 DeltaE (CIE94) (or 3.6 DeltaE
CIELAB) from the average, with the main difference being
the chroma (Delta_C* = -2.3) and hue (Delta_h*=+2.6).
In effect, they are on each side of the average both in
hue and chroma.
Compared to an average, both charts are OK (as I mentioned
in a previous email, the red, blue, orange-yellow and
purple are the colors which show the most variability in
the ColorChecker).
For critical work, it is always better to use your own
chart measurements, but for "inter-user" tests, the
average data is quite good.
Please send me the data on your old chart and I will see
if your socks have affected the other colors too :-).
I would also appreciate if you could also scan the new
chart (in a flat bed scanner) so that I could see the new
dimensions and check marks you mention.
As for the little warning you see, this happens if the
selected color is out of gamut. But this color is not on
the edge of all RGB spaces I could test. Hum...
Danny Pascale
email@hidden
www.BabelColor.com
On Sat, 29 Oct 2005 22:02:02 +0200
edmund ronald <email@hidden> wrote:
I found my old colorchecker today under a pile of old
socks ;)
It actually managed to get flatter in storage, it used
to be warped.
There is a slight diference in size between the old
cardboard-backed
and the new, which explains why Danny Pacale's template
is a slight
misfit. Also, the new has some alignment marks added,
presumably as a
help for profiling software.
And, yes, in incandescent light I clearly see the
difference between
the old memory color red and the new one. LAB Values are
old:(41.8
57.8 29.2) and new:(42.7,51.6,29.8). The difference
between the two
charts is too great for one to be used as a reference of
a print of
the other, I feel.
By the way, i1Share shows me a little warning triangle
in the
color-slice of my measure of the old chart, but not the
new. I wonder
why ? I did it twice, two warnings .
Edmund
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