Compositing Secrets Everyone Can Use Pt. 4 - Advanced Alphas
COW Library : Adobe After Effects Tutorials : Simon Ubsdell : Compositing Secrets Everyone Can Use Pt. 4 - Advanced Alphas
Welcome the fourth tutorial in this series on the basics of compositing theory in which we're going to be digging deeper into an area that I know has been tricky for a lot of people to understand: premultiplication.
I think it's safe to say that everyone working in video needs to have a solid understanding of this in order to avoid the traps that it can lay (we all work with premutiplied and unpremultiplied images every day of the week), and understanding the numbers is by far the best way of grasping what's important to understand.
Appreciating the maths makes it really easy to see what's happening, whereas simply talking about the concepts in the abstract can be very difficult and confusing.
I've been a film and video editor for over 30 years as well as being involved in motion graphics, sound design and mixing, music composition, visual effects and compositing, 3D modelling and animation, and colour grading, not to mention writing, directing and producing, and most recently, software development.
I am also a developer of plug-ins for the video post-production market having released a range of successful and acclaimed products both under the Tokyo brand and as Hawaiki with Robert Mackintosh.