[. . . ] Do not attach the following accessories to the lens, as they might damage the lens CPU contacts: Auto Extension Ring PK-1, PK-11/11A, Auto Ring BR-4, and K1 Ring. Other accessories may not be suitable when this lens is used with certain camera bodies. [. . . ] When using a tripod, attach it to the lens' tripod collar instead of the camera. To attach the tripod collar to the lens, follow these steps: 1 Loosen the tripod collar lock screw 1 slightly. 2 Insert the lens by aligning the tripod collar alignment index on the lens with the mark on the tripod collar. 2 3 Turn the lens to an appropriate position index 3 (three indexes are provided every 90°) on the tripod collar by aligning the tripod collar alignment index on the lens, then tighten the screw. (If the screw is not tight, the lens may accidentally come off the tripod collar. ) When holding your camera by its handgrip and rotating the camera in its tripod collar, your hand may bump into the tripod, depending on the tripod in use. Pull out the lens hood by rotating it slowly until the click-stop position is released and the hood moves smoothly. Then, turn it counterclockwise (as viewed from the front) to secure it in the extended position. Because the lens hood is not detachable, slide it back to its click-stop position when not in use. This may cause the lens to drop, due to its own weight, and become damaged, if it hits something hard. To remove dirt and smudges, use a soft, clean cotton cloth or lens tissue moistened with ethanol (alcohol) or lens cleaner. Wipe in a circular motion from center to outer edge, taking care not to leave traces or touch other parts. [. . . ] ) Detachable tripod mounting collar; rotatable through 360°, indices every 90° 77mm (P = 0. The first values are for the PK-12 ring used alone and the other ones for the PK-11A­PK-13, PK-11­PK-13, or PK-1­PK-3 rings together. [. . . ]