my brother called with a Photoshop question which has me completely stumped. he also insisted that this was something he had learned from me, a shortcut.

select copy and paste or apply only luminosity [highlights] to an image with a single shortcut?

Not unless it's an action, etc., that you've created yourself.

one click on you adjustment palette the "color balance"

click that shit and you have access to low mid and hi luminosity controls

Maybe he's confused by the purpose of an alpha channel - which could be dealt with in an easy one-step.

Or the luminosity layer transparency option.

thank you all...