Movable lens hood mechanism of a zoom lens

A zoom lens comprising:

• a plurality of lens groups which are moved with respect to each other to change a focal length of said zoom lens;
• a focusing lens group positioned behind said plurality of lens groups and driven in a direction of said optical axis to bring an object to be photographed into focus;
• a first cam barrel having at least one cam groove on an inner peripheral surface of said first cam barrel, at least one of said plurality of lens groups being moved in said optical axis direction by rotation of said first cam barrel in accordance with a profile of said at least one cam groove;
• a second cam barrel which is fitted on a front part of an outer peripheral surface of said first cam barrel to be rotatable about said optical axis together with said first cam barrel;
• a movable hood barrel positioned around said second cam barrel and guided in said optical axis direction;
• at least one inward pin fixed to said movable hood barrel to project radially inwards;
• and
• at least one guide groove formed on an outer peripheral surface of said second cam barrel, said at least one inward pin being respectively engaged in said at least one guide groove so that said movable hood barrel is driven forward and rearward in said optical axis direction relative to a frontmost lens group of said plurality of lens groups by rotation of said second cam barrel.