Richard Shiell , Sep 16, 1998; 01:17 a.m.
Your lens, like many of the Series 1 lenses from Vivitar, was made by Keno Precision Optics of Japan. They sold lenses directly to the USA for a while under the Kiron name. Their products are uniformly well-made and dependable, and most, like your macro lens, are extremely sharp as well. Enjoy.