system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are movies filmed in multiple formats simultaneously (2D, 3D, IMAX, etc) while still being able to maintain their cinematic integrity?
gpt
You start with the best quality and prune out stuff to get to the lower ones. 

3d is captured by taking two 2d camera images and using polarized light or alternate frame rates or some other vehicle to make them 3d to the viewer. So when you film 3d you get 2d free by simply not combining the two camera outputs into one, and just going with one of the two camera outputs.  

IMAX is a high resolution, so you simply process it down into a lower resolution film by removing pixels.