Re: Spectros not measuring the same
Re: Spectros not measuring the same
- Subject: Re: Spectros not measuring the same
- From: "dpascale" <email@hidden>
- Date: Fri, 15 Jan 2010 12:21:44 -0500
Hello Mike,
Errors are normal, large errors no, so we need more info.
in turn use either another i1Pro or another vendors unit we see sometimes
a rather huge difference in measurements.
How much on average? (Please indicate the error formula, CIELAB, CIE94 or
CIEDE2000)
I've checked that all settings have been the same -
Including if both units are UV-Cut or non-UV-cut?
Is the measurement backing surface the same in both cases?
These two factors could create a large error for some papers.
On top of that you have to add the error due to inter-instrument agreement.
Assuming both units are in proper order and within their certification
parameters, this is about 0.4 CIEDE94 on average and 1.0 CIEDE94 max for an
i1 (or about the double in CIELAB, so 0.8 on average and 2 max). Please note
that these errors are given in relation to BCRA calibration tiles, and not
an IT8 target, so actual errors wil be higher than these specs.
If comparing to an instrument from another vendor, you also have to consider
the absolute calibration error difference between instruments which,
unfortunately, is not available, but this error is more than the
inter-instrument agreement of each instrument!
Danny
email@hidden
www.babelcolor.com
----- Original Message -----
From: "Mike Stewart" <email@hidden>
To: <email@hidden>
Sent: Friday, January 15, 2010 11:40 AM
Subject: Spectros not measuring the same
I know this is a known issue; but I'm looking for info on the subject. As
an example; if we measure an ECI2002 Random chart using an i1Pro (D50, 2
degrees) and then send the exact same printed chart to a printer and they
in turn use either another i1Pro or another vendors unit we see sometimes
a rather huge difference in measurements. I've checked that all settings
have been the same - the difference is the spectro itself. I've read the
VIGC report and am finding it frustrating to say the least that the
possibility exists that two spectros from the same manufacturer can
measure so differently to each other. This plays total havoc when a Pre
Press house sends proofs to a printer only to have the printer measure the
same color chart and come back with different readings. What does one tell
the customer. Thanks in advance - Mike Stewart
_______________________________________________
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
_______________________________________________
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