Today in class we covered sky replacements in After Effects.
The process is pretty simple and can be done quite quickly. It uses the two effects linear wipe and linear colour key. You need to get two images of setting and place a sky image inbetween these two images before adding a colour wipe to the sky image to make it blend in more to the environment. A linear colour key is then set to the scene image above to make it so that you can see the sky image through the scene image above it. You can then edit the matching tolerance and softness in the linear colour key effect to make the scene look as realistic and natural as possible.
This effect works best if there are little to no clouds in the sky of the setting image as the clouds will show through to the sky layer as when you colour pick the sky you are colour picking the blue and the clouds are white. To get past this if I was editing a sky for an assessment or something I would add an extra step in photoshop before doing any work in After Effects to edit out the clouds.
These are a few examples of sky replacements which I have done during todays lesson: