Transparent Video

This is a subject I have seen all over the internet.  People are always wondering how to get that "transparent" background, so it looks like your subject is walking onto the computer screen.

The good news is, this is REALLY easy to do.

THINGS YOU WILL NEED:
- A Chroma Key Screen (aka green or blue screen)
- Lights
- Camcorder
- Editing software

I am going to assume for the sake of time that you already know how to shoot and light a chroma key screen, so I will skip over that.  I may address those steps in a future post.
 
1. Roll your chroma key screen out all the way so your subject can walk on it.  Frame up your shot so you can see him or her, from head to toe.

 2. Shoot your footage and capture it to your computer.

3. Remove or "key out" the background.

4. Next, make sure you don't have a background selected.  In After Effects, for example, there is a small button in the middle of the screen that, when you hover over it, says "Toggle Transparency Grid."  Make sure whatever is behind your subject has this transparency grib on.  In other words, you want a checked background, not a solid background.

5. Now export your video!  I'll use After Effects again as an example here, although other software should have similar settings.  After you add your project to the Render Queue, click on the output module link.  You will have to select a format that supports an alpha channel.  Flv, Mov and Mp4 are all solid choices.  Next, under Video Output, change the channels to RGB+Alpha. 

6. Click OK and then click render and your video will come out with a transparent background.  All that's left is finding out how to put it onto your website.  Make sure to set it to play automatically and without player controls and it should work.