Webinar – Gamma 2.2, 2.4, 2.6

Presenter: Charles Poynton
Duration: One, 2‑hour session
Date/time: Thu, Jul 11, 2013 11:00 AM – 1:00 PM EDT
Registration: CAD 90 Register


“Gamma” in digital imaging is a terribly confusing topic. Misinformation is widely available. “Experts” disagree. Historical Macintosh gamma was quoted as low as 1.8; some say that 576i video had gamma as high as 2.8 – Why the big range? Even with modern Macintosh standardized at 2.2, like sRGB, there is still confusion. For example, should an sRGB display EOCF have a linear segment or not? Standard gamma for PC is 2.2, for HD is 2.4, and for digital cinema is 2.6. Why are these values different? Why is gamma so complicated?

In this webinar, Charles Poynton will present the big picture of gamma – that is, the nonlinear coding of colour image data. He will outline the basic consideration of perceptual uniformity (related to the lightness L* of colour science). He will relate perceptual uniformity to the camera (and its opto-electronic transfer function, OECF), and he will relate it to the display (and its electro-optical conversion function, EOCF). He will relate the concept of gamma to bit depth at various points in the imaging chain. He will describe the dependence of display gamma upon the luminance available at the display, and upon the display’s ambient condition (illuminance and surround). These explanations will make it clear why different applications (computing, HD, digital cinema) use different numerical parameters for gamma – 2.2, 2.4, and 2.6 respectively.

At the completion of the seminar, you will have a good understanding of how to optimize image creation and display for different viewing environments.

Questions and discussion will be encouraged.

Who Should Attend: The Seminar will be suitable for people in positions such as these:

The attendee should be familiar with digital video, and HD. (Knowledge of digital cinema is not required.) Knowledge of mathematics isn’t required; nonetheless, many graphs and several equations will be shown!

Registration: At GoToTraining, CAD 90. Detailed handout notes – some of which form portions of the second edition of Mr. Poynton’s book – will be provided. For information, contact Charles Poynton, charles@poynton.com, +1 416 535 7187.

Copyright © 2013-07-03 19:25 EDT
Charles Poynton