Do you mean alt clicking the slider in the Levels adjustment dialog? You threw me with the term "tool." yes that works, and as I said, there are many ways to skin a cat. The difference there is that can't see the actual values of your samples, so its just as effective, but offers less data. I am a numbers guy, and I like to know that my highlights are no higher than a certain point, and no lower than a certain point. This stuff becomes more important if the output destination is print. Thanks for that bit - I guess I'd have to make a video of the to demonstrate, since PrtScr won't capture that at activity at all.
Incidentally, the alt-click slider does many things in many areas of Photoshop, so try it out to see where it works. My personal favorites are alt ckicking the Exposure and Shadows sliders, as well as the CA sliders in ACR.
Thanks for poitning that one out
