Transparency issues

[Roland R. kahlenberg]

TO remove blacks, use the Screen Blending Mode. TO remove whites, use the Multiply Blensing MOde.

Use LEvels and crunch the blacks and whites accordingly to ensure that the whites are pure white and the blacks are pure blacks.

You can use the Effect>CHannel>Set Matte if you want an Alpha CHannel whihc the BLending Modes don’t provide.

HTH
RoRK

broadcastGEMs – AEPro Volume 02 (Professional Adobe After Effects Project Files – Now Available).

Adobe After Effects Training in South East Asia.

[Paul Hennell]

Don’t think I’ve ever seen anywhere offering such videos that doesn’t offer a guide/help, but anyway – in a nutshell set your blend mode to multiply. Try other modes or luma key as well to see their effects but multiply is what works best.

—
Only in after effects do children get to pick and whip their parents.
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[Simon Edwards]

amazing that worked fine, thanks so much guys!!

[Alexander Cama]

You could use the older technique of luma keying, just put your clip in a precomp. Add a white solid and use the luma matte mode. it’s under the alpha matte modes in the little pulldown in the timeline window. (I think they are called the track mattes) This will pull a clean luma key, and when you put the precomp in your main comp you will see that it now has an alpha channel.

I say older technique because it’s one of the ways video tape worked with keyable video. Just think as your clip as a separated alpha channel.

[Gunnar Refardt]

I’d rather use Effects/Channels/Shift Channels and set the Alpha to luminance. this way you keep the spatters solid. Please note that white parts of the image stay solid while black parts will be transparent. if your spatters are black on a white background invert the clip before applying Shift Channels.

hope that helps.