[Leica] OT: Luminosity Masks (tho I am using on Leica files...)

[Bob Adler]

I've been delving into the use of luminosity masks in Photoshop for many hours over the past three weeks and find them to be amazingly powerful (see Tony Kuyper). 
Does anyone else use these for image development? If so, any downside that I may be missing?

So far I think buying the tutorials and actions is the best $80 I've spent in many a moon...
Best,
Bob

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