Join Steve Wright for an in-depth discussion in this video Pre-processing the clip for the keyer, part of VFX Keying: Master Course.
- [Instructor] In some situations pre-processing…a green screen or a blue screen with color correction…can dramatically improve the key.…But be careful,…you can also make things worse.…Now there are a million possibilities…to applying pre-processing to improve your keys,…so the examples here are just a few…to get you thinking in the right direction.…So let's start by taking a look at this over-exposed shot.…If we look at the code values up here,…I'm going to sample the blue screen.…
Look at this, 1.8.…Now that blue screen should have a brightness…of maybe 0.7, 0.8, 0.6,…somewhere in that neighborhood.…Now if we look at these whites,…look at this, 2.1, 2.1, 2.68.…Way over-exposed.…As a result keyer produced this very nasty edge.…You see, every keyer has a sweet spot…where it expects the color to be,…and if you go outside that sweet spot…you don't get a good key.…
So what I did was I took the original picture,…just applied this Grade node here,…where I just gained it down to point five,…so I cut the exposure in half.…
Note: This course was created by Steve Wright, author of the seminal book, Digital Compositing for Film and Video. We are proud to host this course in our library.
- Creating an uber key
- Keying green-screen vs. blue-screen footage
- Preprocessing footage
- Building a clean plate
- Making luma keys
- Keying on hue and saturation
- Pasting keys together
- Grain management
- Saving time with garbage mattes
- Using spill suppression
- Improving edges
- Color correcting keys
- Sweetening the comp
- Alternative compositing workflows
- Fixing edge problems
- Using KEYLIGHT, Primatte, Ultimatte, and other tools
Skill Level Intermediate
Photorealistic Lighting with Maya and Nuke (2012)with Mark Lefitz2h 24m Intermediate
Compositing a Sci-Fi Force Field in NUKEwith Steve Wright2h 12m Intermediate
Compositing an Alien Portal in NUKEwith Steve Wright2h 20m Intermediate
1. Keying Workflows
2. Pre-Processing the Green Screen
3. Other Types of Keys
4. Building the Uber Key
5. Spill Suppression
6. Compositing Techniques
7. Color Correcting
How to match grade two clips4m 15s
8. Workflow Examples
9. Sweetening the Comp
10. Fixing Edge Problems
11. Special Keying Solutions
12. Appendix: Keyer Tutorials
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