Dennis, Be aware that ACES is for unrendered images. When would a photographer use unrendered images? Lars Borg

As someone who worked on the initial ACES work, I would emphasize that this is probably not suitable for general digital photography. There is an entire infrastructure that surrounds ACES that involves many different type of transforms and many steps in the workflow. I wouldn't try to apply the logic behind this color space to digital photography because the basic reasoning for the space goes well beyond any of the needs of digital photography. There are transforms which unfold devices into ACES and a Reference Rendering Transform which aids in putting a "film " look into the data on output from ACES. The uses of ACES for video is really aimed at re-rendering of film recorded media to other video standards. The use of ACES within a strictly video workflow is not warranted nor necessarily even possible. It certainly won't have any cost or quality benefits. I will point out that far more research went into the RIMM/ROMM specification (ProPhotoRGB) than has gone into ACES up until this point and that research was aimed directly image reproduction at much higher luminances than ACES which essentially assumes a very dark theater environment. The reason that this work is unknown by photographers is because it is carefully aimed in technological areas that don't apply to general photography and it has been crafted towards the cinema and special effects world. The huge dynamic range and gamut exceed any real world environment and they have been built to accommodate film transform which can expand the gamut far greater than the original scene gamut. The gamut compression required to get an ACES image onto paper is huge and is probably only capable of being handled with floating point data and floating point transforms. The ACES white point is not really D60, it is correlated to D60 but it will appear very greenish to most photographers. I'm not sure the mechanism used to transfer data in motion picture and CGI industries that create images with the intent of dark viewing conditions and extreme gamut requirements, is a good match to the imaging requirements found in most photographic applications today. Regards, Tom -----Original Message----- From: colorsync-users-bounces+tlianza=xrite.com@lists.apple.com [mailto:colorsync-users-bounces+tlianza=xrite.com@lists.apple.com] On Behalf Of Dennis Dunbar Sent: Thursday, January 26, 2012 5:44 PM To: colorsync-users@lists.apple.com Subject: IIF/ACES colorspace for video? I just heard about a new color space being adopted in the video world and wondered if anyone here knew about this and could explain a bit more about how it might fit in with the more standard color management practices we've used in the stills world for so long. Here's a clip from an email sent to me by Thomas Wall giving a brief explanation: "The ACES standard color space and the Image Interchange Framework that the Academy of Motion Picture Arts & Sciences has developed, and that is being adopted by SMPTE (among others), is almost unknown among photographers. This color space and interchange format will increasingly become the standard way of transferring files and archiving data in the motion picture and CGI industries. Photographers should also be using this format for the same reasons they do. The color space encompasses the entire visible spectrum, the entire CIE tri-stimulus gamut of human vision, and then some – wide enough to hold data from every foreseeable camera sensor and display technology without data loss due to out-of-gamut color coordinates. ACES is a linear color space; there is no baked-in gamma. It therefore matches the physical nature of light, the way that light sensors actually record it, and the way that computer graphics rendering is done. (Gamma adjustments are done as part of the output transforms for specific devices.) It is stored in floating point format, not as integers, and therefore has a dynamic range that goes from black to almost the intensity of the sun. It has a much more reasonable white point (D60, a standard daylight, and close to the REC709 white point used for HDTV) than ProPhoto RGB, and is larger than that color space. This color space, and the physics and logic behind it, are what we should be using these days; and products like LightRoom and CaptureOne should be able to produce and use it directly. We need to move beyond the dark ages of color management and image interchange standards. Whatever pressure we or the APA can apply to those software vendors, we should." Thanks! Dennis Dunbar Blog: http://www.dunbardigital.com/blog/blog.php Website: http://www.dunbardigital.com Twitter: http://twitter.com/DennisDunbar _______________________________________________ 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/tlianza%40xrite.com This email sent to tlianza@xrite.com The information contained in this e-mail and any accompanying attachments may contain information that is privileged, confidential or otherwise protected from disclosure. If you are not the intended recipient of this message, or if this message has been addressed to you in error, please immediately alert the sender by reply e-mail and then delete this message and any attachments. Any dissemination, distribution or other use of the contents of this message by anyone other than the intended recipient is strictly prohibited. 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