Pentax 100-300mm F/4.5-5.6 SMC F K Mount Autofocus Lens Review

The Pentax 100-300mm F/4.5-5.6 SMC F is a budget telephoto zoom designed for Pentax K-mount cameras. With a 12-element optical formula and a maximum magnification of 0.25x, it covers a useful focal range for wildlife, sports, and portraiture at an entry-level price point. The minimum focusing distance of 1.5 meters and variable aperture are typical for affordable telephoto zooms of this era.

At $74 on the used market in excellent condition, this lens offers accessible reach for Pentax shooters on a tight budget. The 58mm filter thread and compact construction make it relatively portable, though the variable aperture means light gathering drops off as you zoom in. It's a straightforward option for those looking to extend their range without investing in modern or premium glass.