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 EF and EF-S lenses refer to the mount type of the lens, which also differentiates between the sensor type. At the time this is published, Canon offers two sensor types in its DSLRs â full frame and APS-C (or crop sensor).