Studio Reference Displays –
Technology, Standards, and Missing Standards

Sat. Nov. 12, 2011
Location: Technicolor, Theatre 1, Downtown Toronto
9:00–12:30
Presenter: Charles Poynton
Duration: 3.5 hours
Registration: CAD 180.00

(or CAD 300.00 for both this seminar and the afternoon seminar, Scene-referred Linear-light Workflows)

Detailed seminar notes will be provided, including material from the forthcoming second edition of Digital Video and HD Algorithms and Interfaces. Off-site lunch is included, from 12:30 to 13:30; you will have a chance to socialize with your colleagues.

If you're interested, call or send e-mail!

BREAKING NEWS: We’ll have a Sony BVM-E250 AMOLED display on hand to demonstrate.

Synopsis:

For the last decade or more, creators of HD content have relied upon BVM-class CRT displays to make critical creative tone and colour judgements of their material. However, broadcast-grade CRT displays are no longer commercially available. It is questionable whether displays currently being advertised as “Grade 1” actually meet the needs of high-end content creators, and it is not yet clear exactly what specifications are required of emergent studio displays.

In this seminar, I will discuss issues concerning faithful display of content in the post-CRT world. I will outline the behaviour of BVM-class CRT displays, and introduce the “GOGO” model, which incorporates gamma of about 2.4 (not 2.2, as commonly assumed and documented in white papers by companies such as Sony and Panasonic). I will describe how LCD and plasma displays can be made to correspond to the BVM characteristics. I will discuss how gain and offset adjustments (commonly called CONTRAST and BRIGHTNESS) are introduced, why those names conflict with the common usage of the words (which refer to perceptual phenomena), and how the CONTRAST and BRIGHTNESS controls effectively perform the reverse of their names. I will introduce the recent ITU-R Rec. BT.1886 on elements of a standard EOCF for HD, augmenting BT.709. Finally, concerning image acquisition, the best-fit power function to the BT.709 camera “gamma” is not 1/2.2 or 0.45 as commonly assumed (and documented in white papers by companies such as Sony and Panasonic), but 0.51. I will describe why the 0.51 value is appropriate, and I will outline the origins of the confusion between that value and 0.45 (or “2.2”).

I will outline the technology of modern displays – LCD, plasma (PDP), OLED (AMOLED), and projectors, describing their advantages and disadvantages of each for mastering digital cinema and HD content. Many LCD displays have LED backlights, and some have RGB LEDs that offer wide colour gamut. I will describe this feature. Some consumer displays are advertised as having xvYCC, x.v.Color, and/or Deep Color features, which are also features of recent versions of HDMI. I’ll describe these features. Dolby’s HDR display uses a spatially modulated backlight – or, as Asian manufacturers describe it, “local dimming.” I will describe the advantages and disadvantages of this technique. Finally, some studios are mastering HD content on digital cinema projectors or industrial-grade DLP projectors. I will describe how to master with a projector, and I’ll explain how mastering with a projector differs (technically) from mastering on a CRT.

Copyright © 2011-11-08
Charles Poynton