So you’ve decided you want to shoot with a sight on your bow, and now you’re going to have to choose an aiming device. There are only three choices – aperture, scope or pin. You attach one of these to a sight body, and then use it to direct the bow so your arrow hits where you want.Take note – not all sight bodies come with an aperture, pin or scope. You might have to buy one separately, but you need both parts for the sight to function. So if you’re looking at buying an HHA Pro Scope, for example, understand that you would still need a sight body to attach the scope to your bow.The aperture, scope or pin extends out in front of the bow, above the arrow, perpendicular to the riser. It must be adjusted to reflect the flight path of the arrow at the distance you’re shooting. At full draw, the archer places the aperture, scope or pin on the target to take aim. It’s imperative the archer’s eye and aiming device are on the same plane for every shot, to promote consistent accuracy.APERTUREThese are small circles or squares primarily used by Olympic-style, recurve archers. The aperture might have a pin or a dot in the center, which is pasted to the bull’s-eye as the archer aims.SCOPEThis is a large round housing that mounts to the sight body, and it’s used only by compound archers. The scope might have a lens in it, which can magnify the view of the target anywhere from 2-8 times its size. That lens might have a dot in the center, which is pasted to the bull’s-eye, or there could be a fiber-optic sight pin or set of crosshairs in the center of the scope housing.PINA pin is a simple piece of metal or plastic, with a rounded end that serves as your aiming point. These days, the tip usually is the very end of a fiber optic strand. The strand gathers light, so that the aiming point glows. Sight pins can be used by recurve or compound shooters. A sight body might have just one pin, or several, which can be set at different yardages. Pins are especially popular among bowhunters.