Tripod Mount Ring D for EF 100mm f/2.8L Macro IS USM The EF 100mm f/2.8L IS USM, part of Canon’s prestigious L series, and first featuring an Image Stabilizer with angle and shift detection that is highly effective at close focusing distances. L series Quality The lens embodies Canon's highest standards of L-series optics, build quality, reliability and operability. A robust construction includes dust and moisture resistant seals to protect against harsh weather conditions. Hybrid Image Stabilizer The new Image Stabilizer designed specifically for inclusion in a macro lens. It is able to correct lens shift movement as well as the angular movement that most IS systems can correct. This provides 2-stops of correction during 1.0x magnification, increasing to 3-stops at 0.5x magnification and 4-stops during normal shooting. Ultra low dispersion (UD) lens element ensures high image quality A UD element within the lens design effectively removes chromatic aberration. This allows for excellent image quality with high resolution, high contrast and excellent colour reproduction. Focus limiter switch To enhance the photographer’s use of the lens, it is fitted with a 3 position focus limiter switch. With limits for close up subjects, distant subjects and all subjects, the user is able to increase the autofocus speed making quick shots a possibility. Beautiful background blur with 9 blade circular aperture A circular blade aperture helps to create attractive, even background bokeh when isolating subjects at wide apertures. Fast quiet auto focus The ring USM (Ultrasonic Motor) drives extremely rapid auto focus with near-silent operation. Full time mechanical manual focus override is available without having to switch out of AF. The lens offers a minimum focusing distance of 0.3m.