Re: Monitor Calibration
Re: Monitor Calibration
- Subject: Re: Monitor Calibration
- From: Graeme Gill <email@hidden>
- Date: Mon, 16 Nov 2009 14:43:51 +1100
J.Raimar Kuhnen-Burger wrote:
To reply on the wish about frank opinions from other scientists: We´ve
evaluated at least 20 and up to 100 units of the following devices in the
past 18 months to get an idea about the precision, repeatability and inter
instrument agreement in real world usage for a scientific research project.
Thanks for these numbers, they are very interesting.
Rev.D performed equal to the colorimeters. On the 72% white LED and 92% NTSC
CCFL with only 0.3cd/m2, the EyeOne pro started to created more noise in the
darks and had a lot of questionable readings. As far as I know, the Spectro
is not able to set individual integration times with different luminance
levels (in contrast to the colorimeters). The visible result can be
It depends on the drivers. My drivers for instance use a variable
integration time on general emission or ambient readings, and a fixed
integration time for display measurements in an attempt to improve
the consistency of the latter. By doing a display white measurement first
it can switch integration times to maximize them without suffering
from sensor overload. I guess the fully adaptive mode could
be used if it proved to be a better choice overall.
92% and 102% unit in comparison to the Minolta Spectroradiometers. However,
there is no visible difference between the Colorimeters and the EyeOne pro
in real world perception tests. Therefore - according to our tests - there
is a limitation of the EyeOne regarding the spectral interval, but is has no
or little effect on the color representation on the selected displays.
Internally the i1pro samples at about 3nm, and integrates the readings
into wavelength calibrated 10nm bands. The filters are complementary
(ie. sum to flat), so any loss will be due to the physical gap between
the CCD cells. Given the moderate aperture which will spread
a single wavelength out somewhat, it would be surprising if
this was a source of error. This leaves the matching of the weighted
bands to the CIE curves as a possibly larger source of errors in such
a spectrometer, and a situation in which applying the weightings
at 3.3nm intervals may have a slight advantage.
To summarize, the EyeOne Pro Rev D (the A/B Revs performed far less good) is
well suited for today´s displays except the extreme dark readings. All
Colorimeters need an additional correction matrix on wide gamut and white
LED displays. Additionally, 2 of the 3 evaluated colorimeters suffer from
poor inter instrument agreement. The DTP94 (not available from Xrite any
more) performed close to the EyeOne Pro in regards of inter instrument
agreement and with a correction for wide gamut, it showed the best results
even on the displays with lower black luminances.
You show inter-instrument agreement, presumably against the
Minolta CS200, CS1000 and CS2000, but do you have any
numbers for intra-instrument agreement ?
cheers,
Graeme Gill.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden