Creative COW SIGN IN :: SPONSORS :: ADVERTISING :: ABOUT US :: CONTACT US :: FAQ
Creative COW's LinkedIn GroupCreative COW's Facebook PageCreative COW on TwitterCreative COW's Google+ PageCreative COW on YouTube
ADOBE AFTER EFFECTS:HomeForumBasicsExpressionsTutorialsPodcastsAE TechniquesCreative Cloud DebateFAQ

What is the difference between ALPHA and LUMA?

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Share on Facebook
Daniel HaskettWhat is the difference between ALPHA and LUMA?
by on Apr 2, 2005 at 12:00:48 am

Hi there

Ive just been wondering, what is the difference between luma and alpha? Just because when I do stencil luma on a drawing it works, as it takes out the drawing from the layer beneath, however when I do stencil alpha it does nothing. Just wondering what the difference is between the two. Also when you have a layer with stencil luma, it affects all layers below it, but is there a way of picking a layer beneath it and saying I dont want it to affect that layer? I read somewhere about nesting a composition, but I dont know what that is?

cheers in advance!

dan


Return to posts index
Reply   Like  

MattRe: What is the difference between ALPHA and LUMA?
by on Apr 2, 2005 at 12:16:18 am

A luma matte makes a matte using the luminance of a layer. An alpha matte makes a matte using the alpha channel. The alpha channel defines the transparency of a layer and can be created in photoshop to isolate a certain part of your image.

"is there a way of picking a layer beneath it and saying I dont want it to affect that layer?"
No. Since "stencil luma" is a transfer mode, it effects all the layers beneath it. You can use
track mattes to matte individual layers.

I'd suggest you look towards the After Effects help file or consult Trish and Chris Meyer's After Effects books. You'll learn this stuff a lot quicker and more in-depth than asking pretty straightforward questions on the board.


Return to posts index
Reply   Like  
+1

Eric ChardRe: What is the difference between ALPHA and LUMA?
by on Apr 2, 2005 at 1:09:30 am

[Daniel Haskett] "what is the difference between luma and alpha? Just because when I do stencil luma on a drawing it works, as it takes out the drawing from the layer beneath, however when I do stencil alpha it does nothing. Just wondering what the difference is between the two. Also when you have a layer with stencil luma, it affects all layers below it, but is there a way of picking a layer beneath it and saying I dont want it to affect that layer? I read somewhere about nesting a composition, but I dont know what that is?"

All these questions are answered in the manual.





Return to posts index
Reply   Like  

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Share on Facebook


FORUMSTUTORIALSFEATURESVIDEOSPODCASTSEVENTSSERVICESNEWSLETTERNEWSBLOGS

Creative COW LinkedIn Group Creative COW Facebook Page Creative COW on Twitter
© 2014 CreativeCOW.net All rights are reserved. - Privacy Policy

[Top]