It is very difficult (and tedious) to make a selection of the sky in an image like this. There are so many small details jutting into the blue sky that you will almost always end up with some area excluded. The best way to deal with uneven, broken horizons is to shoot in HDR.
You might want to try a different approach in post processing. Instead of using the Magic Wand try darkening the image globally by using Levels on an adjustment layer. Now add a layer mask and paint the foreground back in using the Brush (B) tool set to black. By changing the brush size, softness, and opacity when painting near the edge of the rock formations you can probably get a pretty believable image with a little practice and a lot of patience.
Sun 30-Jun-13 12:02 AM | edited Sun 30-Jun-13 12:03 AM by quenton8
I have been learning over the last year or so to use layer copies, modified for an effect and the masked.
Initially, and partly because of what I had read, I was trying to work with selections, but I found that the masked layer was way easier to work with, and I find I am going that direction more and more.
I tried both on this photo and found that the masked layer was WAY easier to use.
Ive been playing with channels lately not an expert! Try selecting for colour. I'm using CS6 but I 'think' this is doable in CS2.
- I copied your JPG into PS and selected only the blue channel turned off Red & Green, - Control-Click on the Blue Channel, - Control-D to deselect all to remove the marching ants from the rocks, - Magic wand through the sky, blue - select a Levels Adjustment to produce a Layer with the sky selected in a Mask, - darkened the blue sky with the Level Adjustment.
Obviously too much (could use the Opacity Slider to reduce the effect) but the point is to show the effect and the edge problem. It might work with the original image to give you a better edge at the sky/rock interface.
I realize you said you wanted to do this using a selection with the magic wand, but I think a better approach is to use the color balance to bring up the blue and cyan (take down red and yellow), and then use a soft edged brush to mask off the foreground. This took me about a minute to edit. I find it much easier than trying to make selections.
You may be running into a problem with the sharpening applied to the skyline. The lack of color information in the very distinct sharpening halo makes selection based on not-land difficult. If you can back up your edits to before you have applied any sharpening you might have more success. I don't recall if CS2 is before the refine selection edge feature made it into the tool set. One can always set a slight gaussian blur to the layer mask and paint it away where the effect is inappropriate.
Some of the methods mentioned in other answers are fine stand-ins for the magic wand (& in later versions the quick selection tool). A third would be Select/Color Range which can select the sky. Put the eyedropper in the sky and either adjust the sensitivity with the fuzziness slider or shift-click to increase the number of colors under the selection. As with any other selection method, choosing an adjustment layer will populate the mask with the current selection.