Maya’s luminance depth preset can do a lot of things for the finished look of your animation, with a minimal expense of render time. You can use it to generate post controlled fog or darkness, depth based compositing of elements, or for a good, post controlled focal blur.
Maya’s Z Depth channel rendering has a few problems. It’s not easily read or used by your favorite compositing program, it is not anti-aliased so you may get jaggy side effects by using …