I'm assuming that you're only looking at Pentax lenses. If so I think that for your stated purpose you would be best going for the 2.5. The extra stop would be invaluable for available light. I have the SMC Takumar version and it's very nice. The 135 2.5 is quite a bit more expensive than either of the 3.5's in similar condition however, unless you're looking at the Takumar Bayonet which has a lousy reputation.
At 04:38 PM 9/10/2002 -0400, you wrote: >So, I've got to play photog at an upcoming wedding reception (they already >know they get what they pay for), and while I'm not willing to buy lots of >new gear for something like this, it IS an opporunity to slip something >past the lady who controls the purse strings... > >I was originally going to do the bulk of it via an A50/1.4 and the >AF35-70/2.8 (the softer aspects that this lens is reputed to have was a >nice plus), but I'm now considering something in a longer range, if >possible. > >Would one of the 135 in either 2.5 or 3.5 be acceptable? I'm limited to >used, but I see some of those come up in the used section of B&H or >Adorama a few times, and I'm now considering either. So, does the general >population think a good plan, or stick with what I know? > >Oh, and as I said, I'm supposed to just do candids, and since I have no >flash (and couldn't use one correctly if I did), I figured I'd stick to >available light, and big fstops for small DOF. However, I'm starting to >figure that perhaps 70mm might not be long enough... My only other lens is >a cheap Quantaray 70-300 (which would be f4 up to abou;t 100mm or so). > >Obviously, a fast (and cheap!) lens is what I'm looking for. > >-- >http://www.infotainment.org > "The destructive character is cheerful." - Walter Benjamin
