12 parts keying tutorials by Total Training @ Adobe TV starting from basic Color Key to Keylight:
Part 1 – Introduction
Part 2 – About Channels
Part 3 – Color Key, Color Range, & Linear Color Color
Part 4 – Introduction to Keylight
Part 5 – Keylight (Matte)
Part 6 – Keylight (Masks & Color Correction)
Part 7 – Save Presets
Part 8 – Keylight (Source Crops)
Part 9 – Placing Backgroud and Color Correction
Part 10 – Rotoscope (Masking)
Part 11 – Masking + Tracking
Part 12 – Using Filmstrip with Photoshop

