Turn layer colours into selection

[einstein]

Hello,
What is the easiest way to turn a greyscale layer into channel (selection)? So, let's say, blacks will be non-selected, greys will be semi-selected, and whites will remain fully selected?

[Ofnuts]

Open the Channels list, right click any of the R/G/B channels at the top and Channel to selection.

Looks like you are doing luminosity masks?

[einstein]

Yes, that will help, thank you