What isn’t a compositor might be a better question to ask but let’s keep this article on point. In short a compositor is responsible for fusing together elements such as live action footage, 3d animation, stock footage and other sources into a single picture. Sometimes the goal is photo-realism for a motion picture and other times the goal is to exaggerate the world for a TV spot.
A good comparison might be the job of a weldor. Wikipedia has a curious description that I found particularly useful:
“Welders typically have to have good dexterity and attention to detail, as well as some technical knowledge about the materials being joined and best practices in the field.”
In order to complete some shots, a compositor might take on other responsibilities such as modeling and rendering a 3D object or element. Similarly, a weldor might need to fabricate a special tool or object needed for a custom vehicle manipulation.
When a weldor is combining various parts of a bicycle frame, it is important that the parts are fused together properly or the bicycle might just fall apart. Much like a visual effects shot that is not sound, you may see it fall apart on screen.
As we get closer to launching Action Essentials 2, I have been developing a simple guideline for better compositing that is broken down to 7 key points. This is by no means a ‘complete’ guide for every scenario but it should be a good place to start. I plan on detailing many of these techniques in the future but here is a basic overview. If you have some tips that have helped you out in the field, please share them in the comments below.
Here’s another use for the Disintegration Tutorial techniques in a motion graphics example. I used a little bit of shine or a Radial Blur to create a lighting effect as it burns or blows away. You can even play around with the colors to create a magical burn away as well. This tutorial has a cool method for creating light beams if you’re interested.
I sometimes make comps at 24 frames per second instead of 23.976 inside of my tutorials but some people have asked, “What is the correct frame rate for film?” Well, there are a lot of various situations to consider but here are a few good rules.
The frame rate for digital film work is 23.976 so you should use this if you are making a cinematic commerical or movie about robots.
Some video editing applications abbreviate 23.976 as 23.98 but AE requires the more specific frame rate.
Film or not, you should work at the frame rate of your source material.
Non-standard frame rates such as 12 and 15 are great for creating animations for the web or even flash.
If you have multiple fps sources try to conform things to your output format.
The reason I sometimes use 24 fps instead of 23.976 is probably because I’m lazy and web video can be non-standard without many problems. Of course, it is probably good practice to use standard frame rates so that you can easily author to DVD or Blu-ray. Hope this helps but be sure to investigate your specific workflow, so that you don’t run into problems in the middle of a project. Remember PAL & NTSC standards may vary.