Hi Henry, OMMI is in fact addressing a very old problem which has remained dormant for long years. The OM problem is now becoming more proplematic for color-critical work that involves collabortion as the bandwiths of primaries are narrowing down. An individual observer can adapt to any type of display he/she is using but multiple observers cannot converge to the same point. As I have been involved in calibrating/profiling displays since 1992, I have found ways of tweaking displays to make them useful in the simulation of the printed image. Standrad gamut displays with very good uniformity have provided acceptable results for years. They were not perfect but good enough to communicate color information between multiple observers. OM is directly related to the way the display is designed and built. This cannnot be resolved by OMMI or by any calibration/profiling trick . OMMI can only tell you the extent of OM. We are here discussing the problem as it is reflected into the graphic arts industry. The movie industry is already aware of the problem due to dominance of P3 colorspace in their displays. The key people in the production process such as the colorist, the director of photography, the editor, and the director all view the clips on separate displays that are tuned to their eyes. The continuity of color can only be maintained by adjusing each display to its user. As there are limited number people in the production people this is possible. However the creation and reproduction of the still image involves many steps and several decision makers. Hence assigning and calibrating a display to each is not possible. Widening the color gamut worsens OM. OMMI will just tell us where the display sits. Refik Telhan -----Original Message----- From: Henry Davis via colorsync-users <colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>> Reply-To: Henry Davis <DAVISHR@BELLSOUTH.NET <mailto:DAVISHR@BELLSOUTH.NET>> Date: 23 March 2024 Saturday 02:59 To: <colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>> Subject: Re: Monitor/display suggestions? Thanks for the clarity, I thought you were addressing a new problem within a large population of users (lots and lots of wide gamut users). Maybe it’s more the case that you’ve found a specialized field where wide gamut displays are being the most problematic. People in the print world have dealt with displays forever and have found ways to deal with it. It’s not perfect but close enough. If characterization and calibration can’t do the job I don’t see how a rating system is going to offer anything more meaningful than "display X will cause less OM ”, or "display Y is suitable for a single user - not for multiple observers”. Or possibly “display Z is most suitable for home theatre”. Making it easier to figure out which displays are best for certain kinds of work is a noble goal but the problem of OM is going to be left unresolved nonetheless. For most of the side gamut display users I know there is no problem with OM. I see how there can be special areas that might have OM issues such as motion picture creators, theatres, home TVs. As far as I know motion picture creators have worked this out. I don’t know if home TVs have been rated for OM or for compliance with some motion picture industry standard. Old movie theatres with film projectors weren’t especially wide gamut but I’d bet there was still some OM going on. Audiences didn’t mind. Henry Davis
On Mar 22, 2024, at 6:04 PM, Refik Telhan <rtelhan@icloud.com <mailto:rtelhan@icloud.com> <mailto:rtelhan@icloud.com <mailto:rtelhan@icloud.com>>> wrote:
Hi Henry,
Yes it is a rating system that may help the user when making decisions on computer displays.
The metric is puslished by IEC (International Electromechanical Commission) on November 1, 2023 as a Technical Specification (IEC TS 61966-13:2023). https://webstore.iec.ch/publication/67769 <https://webstore.iec.ch/publication/67769> <https://webstore.iec.ch/publication/67769> <https://webstore.iec.ch/publication/67769>>
The calibration applications can change the relative balance between the primaries to match the targeted CCT or adjust gamma for a smooth ramp but they cannot change the spectral shape or the peak wavelength of the primaries. These characteristics are designed into the display by its maker.
Refik Telhan
-----Original Message-----
From: Henry Davis via colorsync-users <colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>>>>
Reply-To: Henry Davis <davishr@bellsouth.net <mailto:davishr@bellsouth.net> <mailto:davishr@bellsouth.net <mailto:davishr@bellsouth.net>> <mailto:davishr@bellsouth.net <mailto:davishr@bellsouth.net> <mailto:davishr@bellsouth.net <mailto:davishr@bellsouth.net>>>>
Date: 22 March 2024 Friday 23:33
To: <colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com> <mailto:colorsync-users@lists.apple.com <mailto:colorsync-users@lists.apple.com>>>>
Subject: Re: Monitor/display suggestions?
Thank you. So this is a rating system aimed at helping with purchasing decisions?
I thought calibration gizmos could already put displays into various states so I'm guessing that wide gamut displays present a bigger problem for calibration routines - not just observers. Right?
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