The Tamron SP A08 200-500 millimeter f/5-6.3 lens for Nikon digital SLR cameras is a high-quality telephoto zoom lens with two low dispersion glass elements that reduce chromatic aberration for sharp, clear images. The Tamron is especially designed for capturing distant wildlife, birdlife, honing in on a face in the distant crowd, or capturing the action of a sports match with precision. This 200-500 millimeter Tamron lens for Nikons offers power, reliability and versatility with a maximum aperture opening of f/5-6.3 and a minimum aperture of 22, so more than just magnifying the subject, you can focus and shoot it the way you want. This Tamron for Nikon is 200 millimeters long without the hood. Add the hood and you have a focal length of 500 millimeters, which is an impressive achievement. The filter effect control adapter is mounted between the lens and the hood in these images. An internal focus mechanism maintains a fixed barrel length when honing in on your subject, while the detachable magnesium alloy tripod mount provides the option for extra stillness while shooting. The Tamron zoom for Nikons is lockable in the position marked 200 millimeters. When locked, the lens stays in for convenience so you easily carry it in the downward position. While you are only able to engage the lock at 200 millimeters, there are marked focal lengths in 50 millimeter increments between 200 millimeters and 500 millimeters to help with precision. Like all large lenses, a tripod is recommended for best results, because even with the best camera person and image stabilization, camera shake will always come slightly into play to compromise the perfect shot. ‘Di’ is the acronym for Digitally Integrated Design, and means they are designed to meet the performance characteristics of Digital SLR devices. They offer higher resolution, control of flare and eliminate ghosting, as well as minimizing peripheral light fall-off and reducing chromatic aberration. The Tamron SP AF200-500 millimeter F/5-6.3 Di LD (IF) is one of Tamron’s new ‘Di’ devices, which were designed with digital SLRs in mind. On this Tamron lens you can switch between autofocus and manual focus, via a little switch that is located on the left side, close to the mount; it is smooth and lets the lens achieve approximately 57 degrees of rotation that range from 2.5 meters out to infinity. You will not find a depth of field scale because, with extra-long lenses such as this, DOF scales are not really needed. There is also not an IR focus identification mark on this lens because it is not needed. This equipment also has a plastic bayonet mounted hood with ribbed interior to minimize reflections, a detachable tripod mount and detachable filter effects control. It weighs 43.6 oz. While the Tamron 200-500 millimeter f/5-6.3 has a Nikon mount, this lens does not have a built-in autofocus motor. Therefore, it is not fully compatible with Nikon DSLRs, such as the Nikon D40, D60, D3100, D5100, etc. The Tamron 200-500 millimeter f/5-6 for Nikons offers versatility, reliability, stability, and the power to bring small subjects into clear, crisp view. This is a great accessory for wildlife photographers who want to capture the eye of the tiger, or for shooting events from back in a stadium when you want to capture the sweat on the singer’s forehead. The Tamron AP lens is built for detailed and high-definition photography from a distance.