Tamron 175DN

Tamron 175DN ... the action of sports with this lens that utilizes the highest level of design technology, which allows it to be just 178mm (7.0") in total length yet maintain a constant F/5.6 aperture. Beautiful, clear, crisp images throughout the zoom range are achieved by the use of two Low Dispersion (LD) lens elements in the front group, which keep chromatic aberrations to an absolute minimum. When focusing, the lens length doesn't change and the front element stays stationary due to an Internal Focusing mechanism, which minimizes corner vignetting and distortion, for sharp images from corner to corner.