Thats because the area you’ve masked around is set to ‘Add’. What should happen is you should only see the background and your subject has disappeared. Go to either the ‘Rectangle Tool’ or the ‘Pen Tool’ and create mask around the area you don’t want to see. I already have a turturial on masking within the ‘After Effects User Guide’ but just so i can finish this turtutial i will cover it breifly. To get rid of the sides you’re going to need to do something called masking. You should see that your greenscreen will disappear and the ‘Background Image’ behind the Greenscreen Footage’ will show through (and the little black bow will turn the colour of the greenscreen). Take the ‘Eyedropper Tool’ and drop it onto your greencreen in the display window. Once you see this window go ahead and select the ‘Eyedropper Tool’ located on the right side of the tab ‘Screen Colour’ (The thing next to the little black box). If you dont see this then you might have the wrong clip highlighted when you applied the effect. Once you’ve applied the effect to your chosen footage you should come up with a window that looks like this: To apply it to the ‘Greenscreen Footage’ you must have the footage highlighted. In this case you want to press on the effect ‘Keylight 1.2’. What you want to do now is scroll down till you find the effect ‘Keying’, highlight it and a sub-bar should come out of it with a couple of keying effects.

If your having trouble locating the ‘Effects & Presets’ _, on top of the window you should see a tab that says ‘Effects’. To apply it to the ‘Greenscreen Footage’ simply click and hold on ‘Keylight 1.2’ and drag and drop it onto your footage. If you type in ‘keylight’ it should come up with an effect called ‘Keylight 1.2’. You now then want to locate the ‘Effects & Presets’ _ on the far middle right of the after effects window. The ‘Greenscreen Footage’ should be on top of the ‘Background Image’ so at this point you shouldn’t be able to see the background image. For example purposes i will be using two pieces of footage The subject on top of the greenscreen and the background image that i want the subject to stand apon creating the scene.

You should already know how to import your footage into after effects.

After effects keylight 1.2