All throughout Aperture, there are Action menu buttons with some great goodies underneath. These little buttons, with gear-like icons, reveal menus that have commands you won't find under the menu bar and are sometimes hard to find under context menus. For example, under the Project inspector's Action menu, you will find the option for "Maintain Previews for Project."

The Action menu on the Adjustments panel has some particularly useful options that you might not be aware of. The top item, Remove All Adjustments, is a quick way to reset an image back to its default state. The next block lets you customize the histogram area (or remove it completely). I would recommend showing the histogram area and also showing the camera/color info. This row of information lets you quickly see an image's exposure information and lens choice. When you're flipping through images in full-screen mode (or full viewer mode), it's a convenient way to see image information without taking screen space. I prefer to hide the auto adjustment buttons, as I don't find them particularly useful.

The next blocks let you control how color information is displayed on the histogram and in the loupe. Here, you can pick between different color formats, such as RGB and Lab, as well as adjusting the sample size--how many pixels Aperture averages--to determine a color value. Averaging over a small area is useful when measuring areas with noise, for example, so that the noise gets filtered out in the color reading.

The last group lets you change how the histogram is displayed. Luminance is a combination of the red, green, and blue pixels that weights each channel similarly to how our eyes do. It gives you an idea of the overall light/dark range of the image. RGB lets you see all three channels' individual histograms at once, and the separate Red, Green, and Blue items let you see each channel separately.

As you look further down the Adjustments panel, you'll find additional Action menu buttons with commands to manage the preset adjustments and default adjustment set. When you see an Action button, make sure to press it to see what lies beneath.