Open Radar

 
Summary:
When using the Lock Screen command in the Apple menu or the Screen Lock button in the Touch Bar (btw, why the opposite word order?) the screen is locked and left on. This is a waste of energy, which is an important concern when on battery power. This is a regression from Sierra where the screen was turned off after this action.

To be honest it’s actually more common that I use this when connected to power because I want to leave Xcode compiling or indexing so the battery concern doesn’t happen so much in practice, but it really bothers me that the screen(s) are on doing nothing useful.

Steps to Reproduce:
Choose  menu > Lock Screen

Expected Results:
Computer should stay awake and locked, and displays should be off.

Actual Results:
Computer stays awake and locked, but displays are left on.

Version:
10.13 Beta (17A315i)

Notes:
Ideally the Mac would be like iOS where there isn’t a distinction between sleeping and being awake with the display off, and long running useful work always continues, but my experience is that the Mac is unfortunately not there yet.