Creative Compositing - Research into VFX and SFX

I wanted to researh into compositing a bit more to get a better understanding of things that can be made from it.

Special effects can be broken down into two categories: optical, and mechanical.

Optical effects are done by manipulating the camera and lighting which makes the scene look different. Things that can do this include: working with a different lense, different lighting, camera movements and angles.

Mechanical effects involves working during a live-action shot and making things look and seem like something they are not. For example: manipulating weather conditions, pyrotechnics and working with scale models.

Visual effects this includes: green screen, creating computer generated imagery (CGI), 3D rendering or animation.

This websites shows before and after green screen - 
http://digitalsynopsis.com/design/movies-before-after-green-screen-cgi/

 This was really interesting to see how they transformed green screen.

Avengers -
https://www.youtube.com/watch?v=MnQLjZSX7xM

Transformers -
https://www.youtube.com/watch?v=btn2tPxjisA

Deadpool -
https://www.youtube.com/watch?v=flqHc0-g1Ao

Guardians of the Galaxy -
https://www.youtube.com/watch?v=yDwmhC_4_IY

More VFX breakdowns from MPC -
http://www.moving-picture.com/reels/vfx-breakdowns/


All these videos and sites were interesting to watvh to see how they get to the final look of the film and how they make it look so real, I hope to achieve a realness with my project.