There are basically 3 different types of sights; fixed pins, moveable pins, and pendulum. All of these have advantages and disadvantages.

Fixed Pins - You typically have anywhere from 1 to 5 sight pins. You set a single sight pin for something like 25 yards and with today's fast bows you should be able to shoot out to 40 yards by holding a little high or low. A lot of hunters like this because they don’t get confused over which pin to use. Others use several pins setting them for distances like 20, 30, and 40 yards. Then you can hold a pin pretty much low or high in the vital at any distance. You don’t need to judge distance exactly this way. You can guess it is over 30 yards, but less than 40 yards. Hold the 30 yard pin high in the vital and you should have a killing shot. Another often over looked advantage is using the sight pins as a range finder. The average Whitetail deer’s body height at your sight pins will be about 5/8” at 20 yards. That means if you have sight pins that are 5/8” apart and the deer's body fits between the pins it is 20 yards away. It would be 5\16” at 40 yards. This only works with pin sights that are horizontal. You can do a little experimenting and learn how to judge distance using your sight pin gap. Another advantage that few people know about is using your fixed pins to make sure you clear brush or limbs. For example, you have a 30 yard shot at a target or animal. At about 20 yards there is a limb that is just above the animals body and you don’t know if your arrow will hit it because of trajectory. Put your 30 yard pin on the target and see where your 20 yard pin is. If it is on the limb you will hit it. If it is above or below the limb you will clear it. The only disadvantage of fixed pins is you many times have to hold a little over or under the target rather than right on it.

Moveable Pins - You have one pin on a sight and it moves up and down. There are marks that indicate the distance. You judge the distance to the target and then move the pin to that distance. The advantage is you always hold on the target. These are popular for target shooting. There are a few disadvantages for hunting. Animals don’t always stay at the same place. You have to move the pin as the animal moves or hold high or low, just like with a fixed sight. There are many cases where a person forgets what distance the pin is set on and then misses. You also have to be able to judge the distance accurately and quickly.

Pendulum Sights - These are designed for treestands. The sight pin swings so when you aim downhill the pin swings to make up for the downhill angle. You generally have to get these sighted for a particular height and yardage and then they will be on at any yardage from that height. They work well when used properly. The reason though that most people shoot high downhill is a change of form rather than the effects of gravity. Today’s fast bows only shoot a few inches high when shooting from 20 feet up and out to 20 or 30 yards. That is not enough to make you miss. Most people drop their bow arm when shooting down, especially at a steep angle or when wearing a lot of clothing. They should bend at the waist. Dropping the bow arm shortens your draw. The peep sight moves up when the string moves forward. It is that peep sight movement that makes you shoot so high that you shoot over a deer. A pendulum sight does not compensate for this. Pendulums also tend to be noise because you have a moving part that moves a lot with the recoil of the bow. The pin also has to be locked in place when shooting on the level.