On Tue, 16 Mar 2021 at 15:44, Todd, Craig <CT@dolby.com> wrote: > BT.2100 is a more complete specificaton as it includes specs on the > reference display and reference environment. > BT.709 display was de-facto CRT. When new display technologies became > available it was necessary to explicitly define the HDTV display. This was > done in two separate Recs, BT.1886 spec'd gamma=2.4 and BT.2035 specs white > at 100 nits and a viewing environment with a 10-nit background. I consider > HDTV a display referred system, i.e. you create a pixel to produce known > color/luminance on the reference display in the reference environment. > yes, I'd actually consider 709/1886 display referenced too because the effective rendering transform from scene to display is defined in terms of the viewing conditions, most edits made to the signal are made on a monitor without transforming back to scene linear, and most outputs from cameras today do not encode using the Rec 709 OETF in the first place, at least not for any of the content we see. Certainly when it comes to mapping content mastered in one set of reference condition to the specific use cases we always map to reference display colourimetry and then back through the new display/conditions on the assumption that the mastering environment needs to be preserved and is often unknown what the actual scene colorimetry might have been and what transformations have been applied as a rendering. I'd do pretty much the same approach for HLG, even though it is possible to obtain HLG unedited from a camera and thus get some focal plane referred relative scene linear, people want images to "look the same" as they saw on some monitor, rather than some vague recollection of the scene. This basically makes images practically display referenced the moment you edit them whilst viewing on a monitor. Kevin -- FRAMESTORE Kevin Wheatley · Head of Imaging [ London ] · New York · Los Angeles · Chicago · Montréal · Mumbai T +44 (0)20 7344 8000 28 Chancery Lane, London WC2A 1LB twitter.com/framestore · facebook.com/framestore · framestore.com
Received on Tuesday, 16 March 2021 17:45:33 UTC