RE: Two monitors, side by side
Wayne, Part of you reply would attribute the visual difference to my deviating from the Standard Observer? This would imply that, given a relatively large number of people seeing the difference in the two display white points, "on average", the consensus is that "they would match"? I confess I have no idea to what extent my color vision deviates from the 1931/2 color matching functions ☹ / Roger -----Original Message----- From: Wayne Bretl <waynebretl@cox.net> Sent: Wednesday, February 5, 2020 1:55 PM To: graxx@videotron.ca; ''colorsync-users?lists.apple.com' List' <colorsync-users@lists.apple.com> Subject: RE: Two monitors, side by side Charles J. Hirsch of RCA, in November 1964, published a paper in the IEEE Transactions on Broadcast and Television Receivers, "A study of the need for color controls on color TV receivers in a color TV system operating perfectly." In this paper he analyzed the effects of differences in spectral response among individual observers with normal color discrimination, as recorded by Gibson and Tyndall in 1923-24. Hirsch's conclusion was that with NTSC primaries (similar to Adobe RGB), adjustments of +/- 20% or more in the proportions of a mixture might be required to nullify the extremes of observer differences. In other words, do not expect that you are a match to the standard observer, and expect to see some difference between displays that have different spectra. I, too, have two disparate monitors, and they do not match exactly to my eye when the i1pro says they should. I use the larger, wider gamut one for judging images and the smaller one for menus. I also note that the mismatch when first turned on is much greater than after 30 minutes of warmup. I suspect this is due to change in the color of the fluorescent backlight as the internal pressure stabilizes. -----Original Message----- From: colorsync-users <colorsync-users-bounces+waynebretl=cox.net@lists.apple.com> On Behalf Of Roger Breton via colorsync-users Sent: Wednesday, February 05, 2020 10:21 AM To: colorsync-users@lists.apple.com Subject: Two monitors, side by side I managed to pull my old CG-21 of the moth balls, to serve as a second display - how could have I ever lived without this convenience? Crazy. Of course, first thing I did was to try to make it "look" like my NEC PA271W. They're both LCD monitors yet, at the same chromaticity and Luminance, they don't look the "same". One is "reddish" (CG-21) while the other (NEC) is "greenish". Any suggestions? / Roger _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl@cox.net
Well maybe... Part of the problem is the small population that has been used for determining the standard observer - the evidence of variability is plain, but it's more difficult to determine the reliability of the average. Plus I believe later research has shown some flaws in the standard observer (but, I believe, smaller than the variation). I haven't take a deep dive into the topic of new data, since the 1931 basis continues to be used and the personal variations (observer metamerism) are relatively large. By the way, individual variations are becoming more of a concern to the movie industry as they move to laser projectors. -----Original Message----- From: colorsync-users <colorsync-users-bounces+waynebretl=cox.net@lists.apple.com> On Behalf Of Roger Breton via colorsync-users Sent: Wednesday, February 05, 2020 11:59 AM To: ''colorsync-users?lists.apple.com' List' <colorsync-users@lists.apple.com> Subject: RE: Two monitors, side by side Wayne, Part of you reply would attribute the visual difference to my deviating from the Standard Observer? This would imply that, given a relatively large number of people seeing the difference in the two display white points, "on average", the consensus is that "they would match"? I confess I have no idea to what extent my color vision deviates from the 1931/2 color matching functions ☹ / Roger -----Original Message----- From: Wayne Bretl <waynebretl@cox.net> Sent: Wednesday, February 5, 2020 1:55 PM To: graxx@videotron.ca; ''colorsync-users?lists.apple.com' List' <colorsync-users@lists.apple.com> Subject: RE: Two monitors, side by side Charles J. Hirsch of RCA, in November 1964, published a paper in the IEEE Transactions on Broadcast and Television Receivers, "A study of the need for color controls on color TV receivers in a color TV system operating perfectly." In this paper he analyzed the effects of differences in spectral response among individual observers with normal color discrimination, as recorded by Gibson and Tyndall in 1923-24. Hirsch's conclusion was that with NTSC primaries (similar to Adobe RGB), adjustments of +/- 20% or more in the proportions of a mixture might be required to nullify the extremes of observer differences. In other words, do not expect that you are a match to the standard observer, and expect to see some difference between displays that have different spectra. I, too, have two disparate monitors, and they do not match exactly to my eye when the i1pro says they should. I use the larger, wider gamut one for judging images and the smaller one for menus. I also note that the mismatch when first turned on is much greater than after 30 minutes of warmup. I suspect this is due to change in the color of the fluorescent backlight as the internal pressure stabilizes. -----Original Message----- From: colorsync-users <colorsync-users-bounces+waynebretl=cox.net@lists.apple.com> On Behalf Of Roger Breton via colorsync-users Sent: Wednesday, February 05, 2020 10:21 AM To: colorsync-users@lists.apple.com Subject: Two monitors, side by side I managed to pull my old CG-21 of the moth balls, to serve as a second display - how could have I ever lived without this convenience? Crazy. Of course, first thing I did was to try to make it "look" like my NEC PA271W. They're both LCD monitors yet, at the same chromaticity and Luminance, they don't look the "same". One is "reddish" (CG-21) while the other (NEC) is "greenish". Any suggestions? / Roger _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl@cox.net _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl@cox.net
Wayne Bretl via colorsync-users wrote:
Plus I believe later research has shown some flaws in the standard observer (but, I believe, smaller than the variation).
Yes. Hence the proposed 2012 observer: <http://www.cvrl.org/ciexyzpr.htm> <http://www.cvrl.org/database/text/cienewxyz/cie2012xyz2.htm> Graeme Gill.
Roger, we did these experiments at Fogra in our softproofing research back in 2009. Even if you are using the most accurate instruments (we used a CS-2000) a numerical match between two different backlight technologies doesn't mean a visual match. The reason is that most backlight technologies have their spectral flanks at the same wavelengths where the CMFs have flanks. So every small shift in wl-sensitivity exhibits a rather huge difference in observed colour. To get an idea see: https://www.fogra.org/en/fogra-research/prepress/researchprojects-prepress/s... So practically: Finetune the whitepoint of the second display as Graeme suggested. Cheers Claas Graeme Gill via colorsync-users schrieb am 06.02.20 um 03:26:
Wayne Bretl via colorsync-users wrote:
Plus I believe later research has shown some flaws in the standard observer (but, I believe, smaller than the variation). Yes. Hence the proposed 2012 observer: <http://www.cvrl.org/ciexyzpr.htm> <http://www.cvrl.org/database/text/cienewxyz/cie2012xyz2.htm>
Graeme Gill.
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-- *Claas Bickeböller* Product Manager Graphic Arts Konica Minolta Sensing Europe B.V. Swiss Branch Dietikon Riedstrasse 6 CH - 8953 Dietikon Phone: +41 43 322 98 04 Mobile: +41 79 861 71 77 Fax: +41 43 322 98 09 E-mail: Claas.Bickeboeller@seu.konicaminolta.eu <mailto:Claas.Bickeboeller@seu.konicaminolta.eu> Website:http://www.konicaminolta.eu <http://www.konicaminolta.eu/>
participants (4)
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Claas Bickeböller
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Graeme Gill
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graxx＠videotron.ca
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Wayne Bretl