Ever noticed rainbow-colored halos around the edges of objects in your photographs? This is known as chromatic aberration or color fringing. Typically, it’s only visible if you look really hard ...

One of the simplest is the official "Halo" logo, available in a variety of colors from Red Dezigns. Along with color, there's a surprising number of sizes, from a 4-inch by 2-inch to a 47-inch by ...