Canon EF 8-15mm f/4L Fisheye USM EF8-15mm f/4L Fisheye USM Instruction Manual - Page 11

6. Hood The EW-77 hood can keep unwanted light out of the lens, and also protects the front of the lens from rain, snow, and dust. Attaching To attach the hood, align the hood's attachment position mark with the red dot on the front of the lens, then turn the hood as shown by the arrow until the lens' red dot is aligned with the hood's stop position mark. Button Removing To remove the hood, hold down the button on the side and turn the hood in the direction of the arrow until the position mark on the hood aligns with the red dot. This hood can be used even when the lens cap is attached to it. ENG-10