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Colour Pipeline for ACES/CGI/VFX with Charles Poynton
Fri 14 October 2016, 10:00 – 18:00 BST
Internationally renowned moving-image guru and SMPTE fellow, Charles Poynton will be giving a one day master class in London about the colour pipeline for VFX and digital imagery.
TICKETS for FULL DAY EVENT: £200 plus £11.50 Eventbrite fee plus VAT
CGI/VFX rendering is performed in scene-linear light colourspace. However, it is traditional to deliver in Cineon printing density (CPD), where certain compromises in colour coding are made. The ACES colour system introduces new methods of handling colour and new colourspaces. Achieving accurate and repeatable colour in CGI/VFX requires an understanding of the colour transforms among these spaces and other colourspaces such as P3, BT.1886 (often mistakenly called BT.709), and sRGB.
Some sources for VFX are created in sRGB space (for example digital matte paintings). In addition, "web reference" imagery (eg, for texture reference) needs to be transformed to scene-referred form.
In addition to the diverse deliverables that are required today (including dailies, or "Quicktimes"), an increasing number of productions will be required to deliver HDR/WCG. We will outline PQ, HDR10, HLG, and BT.2020.
Cameras are now often described as "wide gamut"; but, surprisingly to many people, in colour science a camera does not have a gamut! If a camera system has a gamut limitation, that limit is imposed by the signal processing and not by the optics, filters, or sensor.
There are challenges in calibration of the variety of display devices typically used in CGI/VFX. Owing to variations in display and viewing conditions, the correct "gamma" may not be exactly the 2.2 of sRGB, the 2.4 of BT.1886, or the 2.6 of DCI.
Rendering in RGB components - or any three components - produces only an approximation of correct colour. When esoteric materials are to be depicted (eg, gold, emeralds, rubies), physically correct rendering requires more than three components.
In this 1-day seminar, Charles Poynton will explore these issues. The seminar will be suitable for people with experience in CGI, VFX, computing, and digital imagery. Many graphs and equations will be shown; there will be math. Detailed handout material will be provided.
About Charles Poynton:
Toronto based, SMPTE fellow Charles Poynton is internationally know as an expert in colour imaging systems for digital video, CGI/VFX, and digital cinema. Twenty years ago, he proposed that HD should have “square pixels,” and chose the number 1080 for HD standards and digital cinema. He was responsible for the introduction of the Adobe RGB 1998 colour space. In 1993, he was awarded SMPTE's David Sarnoff Gold Medal for his work to integrate video technology with computing and communications.
Event logistics and promotion is by UK Screen Association and with thanks to Moving Picture Company.
This event will be Charles' own personal views on digital imaging as he sees it today. UK Screen Association maintains a neutral stance on the relative merits of competing technologies.