Sigma 28-200mm f/4-5.6 — early manual-focus superzoom spanning wide-angle to telephoto in one lens.
Sigma's 28-200mm f/4-5.6 arrived in the late 1980s as one of the earliest superzooms to bridge wide-angle and telephoto in a single lens, predating the more famous Aspherical hyperzooms Sigma launched in the following decade.
It spans 28-200mm through a push-pull zoom action with manual focus, in a large barrel reflecting the compromises needed to cover such a broad range in that generation of optical design. Sigma offered it across period SLR fittings including Pentax K, Canon FD, Nikon F, Minolta MD, Olympus OM and Contax/Yashica mounts.
The huge range was the selling point rather than outright sharpness; images soften noticeably toward 200mm and at wider apertures, but the convenience of one lens instead of two or three appealed to travellers and casual shooters.
Secondhand examples are scarce compared with later autofocus hyperzooms. Buyers should test zoom creep, check the manual focus ring turns smoothly through its full range, and inspect for the haze common in large, multi-group vintage zooms.