How to disable antialiasing for render elements?
In Corona antialiasing can be disabled globally, for the beauty pass and all render elements. This can be sometimes useful - for example, to get rid of edge artifacts when creating DOF in post-production using the Z Depth pass.
To learn how to do this, see: How to disable antialiasing completely?
Additionally, in Render Setup > Scene, "Render only masks (disable shading)" option can be enabled to render only the elements which are not dependent on the beauty pass.