It's been a while since I've posted anything relating to the Great Vivitar 28mm Bestiary, mostly because I view the work of compiling those lens variants to be complete. But this is not to say that I don't still shoot with these lenses. Today I ventured out with one of the very special models from that list, the only one to bear the "Vivitar Series 1" name. At f/1.9 it's also the fastest 28mm lens ever made, sharing that honour with the Voigtlander Ultron.
This is a solid mass of a lens, weighing in at 335g. It is 60mm long and, due to its odd flared shape, is 64mm wide at the end of the barrel. I say "odd" but the lens feels very nice in the hand, with a wide knurled focus ring that turns easily and smoothly and stops precisely.
The mount is M42. I have an official Pentax converter to K-mount, and then a K to MFT adapter, so I can use it on my Olympus E-P1. The lens aperture has a switch for A/M. Leaving this on "M", I get automatic metering through the camera body as I change the aperture on the lens.
The aperture dial moves from f/1.9 to f/16 in half-stop clicks. The first full stop after wide open is f/2.8 and I have determined from exposure information that the unmarked half-stop is f/2.4. Wide open the image has the glow typical of very fast lenses with uncorrected aberrations. Remember that for every extra stop, aberrations increase by a factor of nine. After a certain point it becomes simply impossible for the lens designers to come up with an optical formula that will compensate. Many photographers might enjoy using this "glow" as an in-camera effect, but it rarely suits my taste. I am particularly glad, then, that the first click is not at f/2, which would still be glow territory. By f/2.4 the image is completely usable, as the first two sample images here demonstrate.
Bokeh is nice to my eyes when not wide open, but can certainly get busy. Wide open it swirls but not in the over-the-top headache style known to some Russian lenses. You can definitely get creative with the Vivitar if you wish, as the above image illustrates.
The optical formula is 9 elements in 8 groups with an internal focus design that means the lens does not change in length one iota. The down-side is that the front of the barrel rotates, making the use of a polariser annoying. Though I would not generally use a polariser on a wide angle lens, 28mm cannot be said to be very wide in Field of View equivalent terms. On an MFT body this acts like a focal length of 35mm on APS-C or 56mm on 35mm ("full-frame").
Minimum focus is 30cm and there are seven aperture blades. Made by Tokina, the Vivitar Series 1 28mm 1:1.9 was sold in 1978 for $1000 in today's money. No-one except maybe Voigtlander or Zeiss could get away with marketing anything like it for SLRs in this day and age.
I'll conclude my review in Part 2.