• Apple Final Cut Pro

  Sorting out Mattes from keys

  Posted by Phil Dickson on January 26, 2013 at 2:18 am

  Hi there,

  I’m a rookie when it comes to advanced editing techniques and need some help with the following issue.

  I’m working on a corporate video in FCPX

  I downloaded a stock shot of a laptop computer opening up. There was a green screen in the laptop’s screen area and the shot also came with a black/white matte of the laptop screen opening.

  I want to kay onto the stock shot a still jpeg of a web page. I’ve managed to do this for when the laptops screen comes to rest in the fully open position, but am having trouble getting the image to follow the screen being raised up. Hope that’s a satisfactory explanation.

  Would appreciate if anyone can run through the entire process so that I can check to see if I’m doing it right. At this stage I have

  Still jpeg on Primary track
  Black/white matte on V2
  Stock shot of laptop on V3 with Key filter applied.

  I tried keyframing the shot frame by frame (adjusting the jpeg still as I went) but it’s not smooth.

  Thanks

  Phil

  Jeremy Garchow replied 13 years, 7 months ago 3 Members · 5 Replies
• 5 Replies

• 

  Jeremy Garchow

  January 26, 2013 at 4:35 am

  Either the key or travel matte won’t help with the perspective.

  Perhaps Motion, but I know Ae will help here.

  You’ll need to map the corners of the jpeg to the corners of the screen. Does the screen have tracking markers own it or is it all green?
• 

  Phil Dickson

  January 26, 2013 at 4:53 am

  No Jeremy, the shot didn’t have tracking markers on it, something I know bugs the hell out of graphics dudes. Don’t have Ae but have Motion (with a limited knowledge of it – still working thru the training manual)
  Using distort, I can get the right shape and perspective, but tracking through keyframes comes out jittery and jerky.
• 

  Jeremy Garchow

  January 26, 2013 at 5:15 am

  [Phil Dickson] “Using distort, I can get the right shape and perspective, but tracking through keyframes comes out jittery and jerky.”

  Yes, you need to be super diligent.

  Motion has better tools for this.

  Jeremy
• 

  Patrice Freymond

  January 26, 2013 at 1:17 pm

  save for the first frames of the opening of the screen you should be able to get a decent track from Motion’s Match Move in 4 corners mode. Like most tracks there will be some manual adjustments but the bulk of the work should be possible with the tracking tool.

  In fact, since you have a matte for the computer screen, why not track that? The b/w should get you a better track than the actual shot

  patrice
• 

  Jeremy Garchow

  January 26, 2013 at 2:36 pm

  Precisely.

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