Originally posted by micromacro Oh, that may be a problem, since my eyes are not getting younger. Is that a reason why those vivitar lenses are so cheap on ebay? Because, judging from pictures, they are not so "cheap" at all.
I just started discovering old lenses, and found myself quickly addicted.
That problem doesn't really affect value, I've only seen the anodized mounts on some Cosina made lenses, most are bare metal. The Kobori made K mount lenses often have oversized aperture shields that keep them from mounting on Pentax DSLRs, but this is easily fixed.
The low value is mostly due to the sheer number of them available. The Komine made 135mm f2.8 and 200mm f3.5 are great, they even have a good reputation, but still sell for very little due to how common they are. The multiple variations don't help either, unless you're familiar with them you might not know which is the desirable one, so people avoid them all together.
For even more fun you can find really off brand stuff that is identical to the Vivitars. My Super Lentar 21mm f3.8 and Bushnell 35mm f2.8 were both sold under the Vivitar brand, all were manufactured by Tokina.