TIP: Matching up with color samplers

Adding color samplers to your image is a great way to mark the spots you will click with the eyedroppers in the Curves dialog. Problem is, lining up the eyedropper cursor with the color samplers can be challenging. To make things easier, put on the Caps lock key: now the eyedropper cursor will match up exactly with the color sampler. In fact, you'll know the two are perfectly lined up when the cursor "disappears".