Common skin warts (also called cutaneous warts) are raised round or oval growths. A wart may be lighter or darker than the skin around it. Some warts may have tiny black dots in them, often called seeds. The dots are small, clotted blood vessels. Warts may occur alone or in larger groups that merge and form patches.
According to Canon (link):  Canon addressed the âfeedback loopâ in later model IS lenses by introducing an algorithm to the IS detection system to automatically recognise when the lens is mounted to a tripod.
Canon's first iteration of the FD breech-lock, extended forward from the earlier R-and FL-series lenses, utilized a rotating mounting ring at the rear of the lens; the lens body itself did not rotate for mounting. Its minor disadvantage was a somewhat slower lens change than a bayonet.