Alex Nemerosky describes both the SMCP-A 200/4 and SMCP-M 28/3.5 at http://home.att.net/~alnem/html/pentax_primes.html#28
I'm not sure I'd want to get an -A 200/4, nor pay that much: they are going for between $40 [E] and $90 [M] on eBay. I'm also not sure that the -A is better than the -M: all information I've seen says the opposite. I'm very pleased with my Vivitar Series 1 200/3, which you can get for less than $200; although they are scarce, and usually have an M42 mount - even less 'friendly' than an -M series lens. The SMC Takumar 28/3.5 is not the same as the SMC 28/3.5 - see the SMCT specs at http://www.aohc.it/, it has one less element than the 'K', different minimum focus distance, etc... The -M 28/3.5 sounds like a good lens, especially for a performance trade-off against the other Pentax and Nikon lenses. I have a 'K' 28/3.5, and it lives up to its excellent reputation. The lens tests you propose sound very interesting, but the 'bargain' lens at KEH is probably not in good enough condition for a rigorous test: Yoshihiko Takinami advises "Only test lenses in excellent optical and working mechanical condition" http://www.takinami.com/yoshihiko/photo/lens_test/pdml-procedure.html bye, Jim www.jcolwell.ca
