100 millimeter focal length and 1:2.8 maximum aperture. The EF1.4X II; EF2X II extenders cannot be used with this lens. There are no compatible close-up lenses Lens construction consists of 15 elements in 12 groups 23.4-Degree diagonal angle of view Inner focusing system with USM and full-time manual focus option. Closest focusing distance 0.99 feet; 0.3 meter (maximum close-up magnification: 1x) 67 millimetre filter size. Filter Size: 58 millimetre. Lens hood: ET-73 Compatible with 67 millimeter filters Canon's first mid-telephoto macro "L" series lens to include Canon's sophisticated Image Stabilization Near-silent Ultrasonic focusing Enjoy life-size close-up capabilities without an adapter