Well this is easy, but it takes some time.
Open the channels pallet, grouped with the layers pallet.
scroll thru the different colors, ie just the red channel, then just the green channel. What you are looking for is the most contrast between the light and dark area's of what you are trying to cut out. when you find the one that looks the best, duplicate it and make sure you only have that channel selected.
Now using the dodge, and the burn tool, both set about 10-20%, turn part of the picture black and part of the picture white, don't forget you can change each tool in the options bar to work on highlights midtones or shadows. For the big area's you can just use the paintbrush to paint in the white or black.
For the picture I'm using I used two channels, I really only spent 2 or 3 minutes to get what you see here.
Now you have two ugly pictures, control click on one of the thumbnails, that loads it as a selection. turn on the rgb image, and goto the layers pallet. Click on the add layer mask icon, that will hide the area's you just selected.
a couple of things to think about using this method.
you can use levels to refine your mask.
you can soften the mask using a blur filter.
you can stack mask's on top of each other.
it's real easy to retouch your mask you haven't done anything to the original image.
you can adjust the levels of a copy of the original image to brighten or darken the channel before you go off dodging and burning.
here's a few screen captures.
feel free to ask questions if you get stuck.
Bob


