Hello everyone, cant see specific forum for After Effect software so ill ask here…
I work on after effect and want to create the next thing:
Zoom in to the face of one character and then, when i zoom out the character will be in another environment (another background).
What is the simplest way to do that?
I assume i need to use the camera and zoom in to the character`s face, but what after that?
thanks in advance 
The After Effects forum, like several others, is unnecessarily buried. It’s in a sub-section of the Compositing group.
https://forums.cgsociety.org/c/compositing-software/adobe-after-effectsIf the footage of your character has a transparent background, you can simply zoom to the face and change the background to another layer before you zoom out. “Zooming” can be done by keyframing the scale parameter of your layer or switching layers to 3D mode and keyframing camera position.
If your footage does have a background, things get more difficult… You have to remove the background of your character layer before zooming out, so the new background is visible behind the face. If your footage is shot against a green (or blue) screen, you can remove the background pretty easily with an effect called Keylight. Otherwise you need to draw a mask around your character and move the mask to match any movement in the image. This is called rotoscoping, and is often painfully slow… After Effects ships with a lite version of a program called Mocha, which might help with the masking part.
If you want the face to remain somewhat sharp while zoomed in, the character layer should be larger than your composition. For example, a 1080p composition might require the character footage to be 4K or larger. If you have a close up shot of the face only, you could place it over your character’s face and fade it in & out during the zoom. This could work if the zoom effect is very fast.