Originally posted by DMH
I have the option of buying a mint Vivitar Series 1 70-210 f2.8-4, 62mm (3rd version 28... serial number) lens for under ca$100. I have a K100d with the kit 18-55 lens and am looking for a longer telephoto lens. The reviews of the Vivitar are great but it is manual and doesn't have an A setting on the aperture ring.
I've owned this lens and had it for quite a while. It is very very good. But your information is conflicting. You said the serial number started with a '28' which would indicate the lens was built by Komine. The filter size and aperture range is consistent with that same lens. So are you totally sure the lens does not have the "A" setting? As far as I am aware the non A lenses were earlier versions (I've had 3 over the years version 1,3 and 4). It is possible that there were some early versions of this lens without the "A" setting. So if you are sure that's the case then if it were me I'd most likely pass on this lens. $100 is about the max it's worth on today's market.
If it is indeed the 3rd version of this lens with the "A" setting, then at $100 it is a steal. Sharp, fast, solid and most likely the best 70-210 built by anyone of that era*. It's very heavy at almost 2 Lbs. That makes for a fairly heavy kit to carry around.
I've replaced my "A" version Series 1 with a DA 50-200.
* one thing about this lens that is a weakness in my opinion, was that the colours look flat compared to an SMC Pentax lens. It seemed more so on digital than when I used it on film. It's good but the warmth and depth of colour rendition from the Vivitar are not up to the same level as a Pentax lens.
As for the DA 50-200mm It's not the sharpest lens in the world but it's a very good lens none the less. Given all the extra capabilities that an auto focus "A" series lens offers I think it's well worth the extra money to have the DA.
Just a note as to value. I sold both my Vivitar Series 1's this year. The "A" version (3) sold for $212.70 USD and the "M" version (1) sold for $47.00. optically both lenses are very similar but it would seem that few buyers will pay much for a non A lens these days unless it is something super special.