Photoshot technique needed...

I am trying to discover a way to "select" only the darks, or only the lights on a given shot. Ideally, it would not needed to be done with the eyedropper as in "Color Range", as I am hoping to put it into an action. Is there a way to, say, "Select Values" and input "0 to 100" or "155 to 255".

Would Lab Mode, or Alpha Channel be a way to accomplish that?

And if I can be completely greedy on it, have the selection be graduated, so that "0" is 100% opaque and "100" is only 1% opaque.

Thanks,

Rad

I've not yet got to creating my own actions, but in Photoshop CS2 on Windows, I can use

CTRL + ALT + ~ to select by luminosity.
Save Selection As Channel on the Channels pane.
CTRL and D to deselect.
Select the Alpha Channel.
Apply a curve that is on the bottom until you reach the desired value - then on the top.

Optionally reselect RGB and load the Alpha Channel as the selection.


That does everything you want, except being an action.

David