Which 80-200 zoom to keep?

As mentioned in another post, I'm rationalising my older K mount lens collection now I have a Pentax K10D. I have two 80-200mm zooms from the 1980s, one of which I'll keep and the other I'll sell. One is an 'SMC Pentax-M 80mm-200mm 1:4.5', and the other is a 'Takumar Bayonet Zoom 1:4.5 80-200mm'. If one is markedly better than the other, I'd like to keep the better lens, but if there's not much difference, I'll keep the one with the lower resale value. Any thoughts? Thanks in advance.

The M version is likely to be the better lens because it will benefit from SMC coating. Weigh it. If it weighs around 615 grammes its the version 2 lens (12 elements in 9 groups, same as the Takumar lens), if around 555 grammes it's a version 1 (15 elements in 12 groups.

The Takumar lens, despite the kudos associated with the name, is a budget, non-SMC lens.

Edit: I got the version number info transposed.

Thanks for that, most informative. What's the significance of the version number? Is one better than the other? I think it's a pretty early lens, probably from around 1980.

I would get rid of both and replace with an SMC Pentax-A 70-210mm f4.

Iceblinker's advice is sound, The SMCP-A 70-210 lens is superb, the SMCP-FA lens is even better. For digital, the DA 50-200 is perhaps the best.

Don't sell the 'SMC Pentax-M 80mm-200mm 1:4.5' very sharp lens especially at 200mm and objects beyond 30m away. Beautifully made as well which can't be said about current stuff. Mine was better than the M 200mm f/4 prime so I sold that. Fabulous colours on Digital and purple fringing isn't much of a problem with this lens.

Mine weighs 570 grams without the caps.

Sell the Takumar.

shim

OK, thanks for the feedback. I suspect if I sold the two I wouldn't get enough to buy an SMC Pentax-A 70-210mm f4, as my Pentax SMC has a minor 'dink' on the barrel which doesn't affect it optically but would certainly reduce the selling price. I'll keep that one and sell the Takumar, and keep my eyes open for a 70-210mm on the cheap.