Today's Vivitar Series One shouldn't be touched with a barge pole. Sadly as time went on and Vivitar changed suppliers, their Series One line got degraded through cost-cutting in the engineering process. The first version of this lens was made by Kino Precision/Kiron Optical of Japan. The most popular lens was the 70-210 F3.5 Macro zoom available in Nikkor, Canon FD, Olympus OM, Minolta MC/MD, Pentax M42, and K mount and I think Konica too. While Vivitar focused its efforts on the enthusiast market, they put some serious research and development money on the Series One line aimed at the professional market. From the 1960s onwards marketed third party lenses and in the 1970s the 283 flash which I affectionately call the sledgehammer due to the amount of power it had. Vivitar was a photo marketing company founded in 1938 under the original name Ponder and Best that made and sold photographic and optical equipment.
