Creating A Custom Shadow/Highlight Default
By default, the Shadow/Highlight adjustment command decreases the shadows by 50%, but if you'd prefer to have Shadow/Highlight open flat (with no automatic shadow adjustment), you can set your own defaults. That way, you decide how much, and when, the shadows get opened. You do this by going under the Image menu, under Adjustments, choosing Shadow/Highlight, and then dragging the Shadows slider to 0%. Click on the Show More Options checkbox, and at the bottom of the expanded dialog click on the Save As Defaults button. That's it: Now you get to decide if the shadows get opened up, and how much, because everything's set flat.