Weird Halo Around Exported Video with Particular Effect

[megolas]

Hi there,

I have a composition where I used a number of particular layers and masks. When I go to export the footage with a transparent background, it plays transparent in After Effects. Once I export the footage out into a video, it shows up with a strange white background as if there is a layer of white following behind all of the layers like a shadow. I've attached an image of my export settings, a screenshot of the footage mid animation, and a screenshot of the white that shows up upon exporting it. I'm really stumped on this one. Any help would be appreciated.

Here's the screenshot of the footage in AE showing the transparency:

Here's the screenshot of the footage showing up with a strange white background when exported:

[Dave_LaRonde]

Is there a reason you're rendering a Premultipled Alpha Channel?  It's quite rare these days; most applications want Straight.

[megolas · Accepted solution]

Even after changing it to straight, it was still showing up this way. I opened it in Quicktime and it does have transparency, I guess it just shows up very strange in preview. Almost all of the animations I have to make are transparent and I have never had this weird alpha channel looking background show up before in a preview even. Good to know it was just a strange preview though. Thank you for the help!

[Mylenium]

I'm not clear what you are saying. Unless you import and view your clip in a program that actualyl interprets your Alpha channel, of course you will always see a background and not transparency. Seems you have a misunderstanding of something very basic here. Normal media players simply don't care for transparency.

Mylenium