• Adobe After Effects Expressions

  Reversing Levels adjustment with an expression

  Posted by Sean Lewis on October 4, 2017 at 1:21 pm

  Hi all,

  I am working in 32 bit linear and I have added a levels and exposure effects on a plate. Which is a temporary grade while I work. (Do not ask why, long story!)

  In Nuke this process is non-destructive so you can reverse the grade as a post process and not worry about pixel crunch/artifacts.

  In this instance though it is not working the same way.

  Below are the expressions for the following (in the same order)

  Exposure: Exposure

  Levels (Individual Controls:
  Input Black
  Input White
  Gamma

  And I’m linking these to the original effects.

  The exposure one works fine but the levels does not.

  If anyone could help that would be brilliant!

  Thanks in advance

  effect("Exposure")("Exposure")*-1
effect("Levels (Individual Controls)")("Input Black")*-1
1+(1-effect("Levels (Individual Controls)")("Input White"))
1+(1-effect("Levels (Individual Controls)")("Gamma"))

  Sean Lewis replied 8 years, 7 months ago 1 Member · 0 Replies
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