From the course: After Effects Compositing: 1 Intro to VFX
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Prevent alpha channel fringing - After Effects Tutorial
From the course: After Effects Compositing: 1 Intro to VFX
Prevent alpha channel fringing
- So as I said, if your selections are generated by the computer, there's one thing that can come up, which has to do with alpha channel premultiplication. Now, that's a very complicated way of saying fringing. And so if you ever see a foreground come in with black fringes around the edges, you know that you have a premultiplication problem. This text was created in Photoshop and here you can see a transparency layer. So with a transparency layer, there's not going to be any background mixed into the foreground. It's often the case, however, that you don't work with transparency data, but instead with an alpha channel. Now, if I go into Interpret Footage, Main, I can ignore the alpha channel that's in this TIFF image. And now you can see that everything looks just fine. There's nice feathering of the edges against the background, but of course we don't have a selection anymore. If I go to the alpha channel, you can see it's just turned off. So, instead what we want to do is go into…
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Contents
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Essential 1: Know how to match5m 24s
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Essential 2: An overview of moving selections7m 22s
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Prevent alpha channel fringing2m 4s
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Essential 3: An overview of the camera for compositing4m 26s
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Essential 4: An overview of what makes an image cinematic3m 35s
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Push adjustments hard for drama and intensity6m 23s
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Essential 5: An overview of color correction1m 56s
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Use Mask Tracker for color correction4m 10s
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Essential 6: Know how to comp fire6m 37s
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Add heat ripple and glow8m 54s
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Create convincing screen transparency3m 31s
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Essential 7: Develop a "good eye" to go further1m 51s
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