AF Operation. Thanks to its USM motor, the EF-S 17-55mm f/2.8 is pretty quick off the mark when autofocusing. And virtually silent, too. Like other USM lenses from Canon, you can also grab the The new Canon EF 70-300mm f/4-5.6L IS USM is one of the company’s professional L-series models, in traditional off-white with the distinctive red ring around the front. It sits alongside the EF 70-200mm f/4L IS USM and EF 100-400mm f/4.5-5.6L IS USM as a reasonably priced middle-ground optic, giving full-frame users a nice extra stretch from Lightweight telephoto zoom. This 4x telephoto zoom lens is ideal for the budget-conscious photographer with an interest in shooting sports, wildlife or portraiture. In common with other telephoto lenses, the EF 75-300mm f/4-5.6 III compresses perspective and allows the photographer to restrict depth of field. A compact and lightweight 300mm super-telephoto lens with Image Stabilizer(IS), similar to EF 75-300mm f/4-5.6 IS USM. The Image Stabilizer shifts a lens group(11th to 13th elements) in parallel to the film plane. Camera shake is a major cause of blurred images especially with telephoto lenses. The IS system helps resolving this problem. The newly developed Micro USM makes autofocusing quicker and quieter. The improved zoom mechanism also makes zooming smoother. The front part of the zoom ring now sports a silver ring for a luxury touch. Buy: Canon EF 75-300mm F/4-5.6 III USM Autofocus Telephoto Zoom Lens - USA Warranty MFR: 6472A002. Color: Black. Product Details. Canon EF 75-300mm f/4-5.6 III Lens offers great optics. Offering Super Spectra coating, this feature has been applied to individual elements to reduce lens flare and ghosting in order to achieve high contrast and accurate colours. This lens offers a seven-blade diaphragm to produce smooth and pleasing bokeh. Has full-time manual focus. Canon EF 70-200mm f/4L IS II USM. Canon EF 75-300mm F/4-5.6 III USM. With full-time manual focus, you can move the focus ring whilst it is in AF (autofocus) mode. This means that you can make manual adjustments once the AF has finished, without changing to manual mode. Unless you're gong to be shooting from larger distances, the 55-250 is a better general purpose nature photography lens for your T3. Image Stabilization (IS). The EF 55-250mm f/4-5.6 IS has it, the EF 75-300mm f/4-5.6 doesn't. IS lets you shoot at a slower shutter speed before camera shake becomes an issue. YB9adww.