Displacement preview inconsistency in Maya’s Viewport 2.0
(Maya 2017 Update 3).

• If you connect a 16 bit/channel grayscale image as displacement you’ll get a correct preview. The preview and the render will be identical.
• If you connect a 16 bit/channel RGB image as displacement you can get a correct preview, but an incorrect result if you converted the image in Photoshop, with the default Color Settings*.
• If you connect a 16 bit/channel RGB image as displacement you can get a correct preview and a correct result if you converted the image in Affinity Photo.
• If you connect a 8 bit/channel grayscale or RGB image as displacement, the preview and the render will be different.

* The preview and the render will be identical but a bit different from the original (16 bit/channel grayscale version) results.
If you have a 16 bit/channel grayscale image (usually it’s untagged) you need to assign the sGray or the Gray Gamma 2.2 grayscale profile to the image, than convert to sRGB. In that case the results will be perfect.
If you choose Affinity Photo to convert the image, the results will be correct (Affinity using a different grayscale profile as default).

p.s.

• In every case (with correct profile conversion) the rendered results will be almost (small differences between 8 bit/channel and 16 bit/channel) identical.
• In the file node choose Raw as Color Profile for Height maps.

Previously I forgot to add the Viewport 2.0 preview to the post.
Here it is:

Cheers, D