How do I turn a b&w image into a mask?

[DaVinci]

Is it even possible in photoshop to take a black & white image and have that image BE a mask for another?

[Xaran]

Use apply image.

Christine

[Nasturtium]

http://www.planetphotoshop.com/desig...annel-tut.html

[mistermonday]

DaVinci, welcome to Retouch Pro. In the channel palette of your B&W image select all and Copy. Now go to the image containing your layer mask. Alt+Click on the Layer Mask. Then Ctrl V to paste the grayscale image into the layer mask. Once agian Alt+Click the layer mask to return to the normal layer view.
Regards, Murray

[Chain]

Or simpler:
1. In the channels panel, ctrl/cmd-click on the RGB channel (loads selection).
2. Now go to your layer and click the little "Add layer mask" button in your layers panel.

If your layer already had a blank mask delete that first, or simply fill your selection with Black and then deselect. ctrl/cmd-i to invert if needed.