I’m not sure what to answer, Mate?
To me, “D50” sounds like “M0” (no special light filtering of any kind by the
instrument) while “D50M2” sounds like “M2”. If this is true then “D50” means
that the measurements don’t take into account (in any special way) the possible
presence of FWA (Fluorescent Whitening Agents) in the substrate whereas “D50M2”
will “filter out” the effects of FWA, giving you a more or less different set
of measurements depending on the presence and strength of FWA in the substrate.
I would be surprised if these options are not already covered in Argyll’s
excellent online documentation.
/ Roger
From: argyllcms-bounce@xxxxxxxxxxxxx <argyllcms-bounce@xxxxxxxxxxxxx> On Behalf
Of Mete Balci
Sent: Wednesday, October 30, 2019 1:14 PM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: question about i1 studio, M2 and spotread
Thanks Roger. I thought it is not mentioned in the i1 studio spec (it only says
white led for the light source), but now I saw D50 is mentioned in the
inter-instrument agreement and short term repeatability numbers, so I guess
that means it is D50. Maybe I can ask now, what is the difference between D50
and D50M2 for -i illum parameter of spotread ?
Mete
* ----
*
* From: <graxx@xxxxxxxxxxxx>
* To: <argyllcms@xxxxxxxxxxxxx>
* Date: Wed, 30 Oct 2019 12:50:02 -0400
Mete,
You can calculate XYZ from spectral data using the published CIE 15-2
equations. I use Excel to carry the calculations. Your XYZ should not be far
from i1 Studio XYZ...
The “standard illuminant for M2” (or M1 or M0) remains the same, it is *not*
M2, because M2 is NOT an Illuminant, D50 is an Illuminant, it is THE Illuminant
used in all (current) ICC color management (other industries use other
Illuminants such as D65). M2 refers to the “light source” inside the
instrument. It is covered in ISO-13655:2009 if I’m not mistaking.
Color and color management are mysterious worlds – hang on to your hat!
/ Roger
www.graxx.ca <http://www.graxx.ca>
From: argyllcms-bounce@xxxxxxxxxxxxx <argyllcms-bounce@xxxxxxxxxxxxx> On Behalf
Of Mete Balci
Sent: Wednesday, October 30, 2019 11:51 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] question about i1 studio, M2 and spotread
Hello,
I am new to color management, and trying to understand the fundamentals. I have
an i1 studio.
Using spotread, I see the spectrum values read (36 values in 380-730nm). I
would like to calculate the color values myself (and hoping to reach approx.
same values to what spotread reports as XYZ).
My question is: i1 studio is using M2 measurement mode and I believe the
standard illuminant for M2 is not specified, am I wrong on this ? If it is not
specified, how does spotread calculate the color values ? Are they reported
directly by i1 display, so actually the illuminant used for the measurement is
propreitary ?
Does -i illum parameter (default D50) have effect on this ? Its default is D50,
but again if M2 does not specify a standard illuminant, how to specify one here
? I see there is an option of D50M2, does it mean M2 is always used with D50 ?
Thanks,
Mete
On Wed, Oct 30, 2019 at 4:51 PM Mete Balci <metebalci@xxxxxxxxx
<mailto:metebalci@xxxxxxxxx> > wrote:
Hello,
I am new to color management, and trying to understand the fundamentals. I have
an i1 studio.
Using spotread, I see the spectrum values read (36 values in 380-730nm). I
would like to calculate the color values myself (and hoping to reach approx.
same values to what spotread reports as XYZ).
My question is: i1 studio is using M2 measurement mode and I believe the
standard illuminant for M2 is not specified, am I wrong on this ? If it is not
specified, how does spotread calculate the color values ? Are they reported
directly by i1 display, so actually the illuminant used for the measurement is
propreitary ?
Does -i illum parameter (default D50) have effect on this ? Its default is D50,
but again if M2 does not specify a standard illuminant, how to specify one here
? I see there is an option of D50M2, does it mean M2 is always used with D50 ?
Thanks,
Mete