How to Perform a creepy sky replacement in Adobe After Effects CS4 or CS5

This four-part Adobe After Effects tutorial from Laurence Grayson shows how to take an ordinary photograph of a building (in this case, a cathedral) and turn it into a spooky looking house from hell. The majority of the work done uses the standard toolset in After Effects CS3, CS4, and CS5. Adobe Photoshop is used for the sky replacement section. Create hellish clouds, eery flickering windows, sheet lightning, color correction, 3D motion and depth of field effects for your next Halloween special!