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.
A redesigned exterior with improved focus ring placement makes manual focus adjustments a breeze. Canon's most compact 50mm lens, the EF 50mm f/1.8 STM has a rugged metal mount, plus an improved minimum focusing distance of 1.15 ft. (0.35m) and a maximum magnification of 0.21x.