Optical apparatus having a function of preventing image blur or shake and having lens barrels of different diameters

An optical apparatus having a function for preventing image shake, said apparatus comprising:

• a first lens barrel portion;
• a second lens barrel portion having a larger diameter than a diameter of said first lens barrel portion;
• an image shake prevention unit including an image shake prevention optical member for preventing image shake, and a holding member for movably holding said image shape prevention optical member, said image shake prevention unit being fixedly held on at least one of said first and second lens barrel portions at a stepped portion formed by said first and second lens barrel members due to a difference between the diameters of said first and second lens barrel portions, and at a position where said first and second lens barrel portions do not overlap each other in a direction perpendicular to an optical axis.

An optical apparatus having a function for preventing image shake, said apparatus comprising:

• a first lens barrel portion;
• a second lens barrel portion having a larger diameter than a diameter of said first lens barrel portion;
• an image shake prevention unit including an image shake prevention optical member for preventing image shake and a guiding member for guiding said image shake prevention optical member with a guide path arranged on a predetermined plane, so that said image shake prevention optical member moves in a direction of said predetermined plane along the guide path, said image shake prevention unit being fixedly held on at least one of said first and second lens barrel portions at a stepped portion formed by said first and second lens barrel portions due to a difference between the diameters of said lens barrel portions.