deepexr and exr: the easy way

There is a simple way to export a deepexr file along with the usual multi-channel exr render as well.

Create your AOVs and render layers as usual
Add a new, custom AOV and call it for example: deep (this will be the name of the generated subfolder).
Switch its driver to deepexr (don’t change any other settings for this driver, it’s ok by default)
render

Done. 🙂

A few things:

If you just rendering in the Arnold render view (or Maya’s own render view) you’ll find the exr file and the deep folder (and its content) inside the project’s images/tmp folder. (With Arnold render view turn on the Save Final Images option.)
Of course you can disable this AOV render layer by render layer:
add an override to your active render layer and than switch off the deep AOV.
If you defined a folder name as a File name prefix (render settings -> common), a main folder called deep will be added next ot your render layer folders.
With this method you’ll get a deepexr file with just the deep data, no colors whatsoever, so it is the most efficient way (the deep data file will be as small as possible).
Rendering multiple render layers and sequences: If you using the basic Arnold licence (comes with Maya) use the Render Sequence command (Render menu) and turn on the All Render-Enabled Layers option.