What makes binoculars good?

Shake can be much reduced, and higher magnifications used, with binoculars using image-stabilization technology. Parts of the instrument which change the position of the image may be held steady by powered gyroscopes or by powered mechanisms driven by gyroscopic or inertial detectors, or may be mounted in such a way as to oppose and dampen sudden movement. Stabilization may be enabled or disabled by the user as required. These techniques allow binoculars up to 20× to be hand-held, and much improve the image stability of lower-power instruments. There are some disadvantages: the image may not be quite as good as the best unstabilized binoculars when tripod-mounted, and stabilized binoculars contain more advanced technology to go wrong, and to become obsolete. They are also more expensive, heavier, and battery life tends to be short. Stabilization is not suitable when tracking moving objects.