Something has changed between CS3 and CS4. In CS3 if you had activated the color sampler tool and were in a Levels Adjustment Layer, you could hold the Option key while dragging either the highlight or shadow slider, a white or black overlay would appear depending on the slider and then move the color sampler tool to the area where you first saw pixels appear to find the area of the darkest and lightest pixel in the image. Now when I try this, the overlay disappears and I have no way to reference where the darkest and lightest pixels are....attempted several key commands and the help files, but nothing is coming up...
Any ideas?
Answered my own question...click on the Levels or Curves dialog box Eyedropper first, then hold Option and move eyedropper into image and overlay will appear.
Nice change,,,