All, Thanks for the comparison info. The dimensions and weights on Boz' site and elsewhere only go so far when it comes to comparisons, so the personal input is valuable. I have the 24 and it's my standard "moderate wide" lens on my *ist-Ds. I'm pondering how I might use the 31. I'm doing a lot of low-light stuff these days and the 31 beckons. The Ds feels a little overbalanced by the 24 to me, so I was hoping that the 31 would make a good standard for the Ds. Maybe I'll wait until Pentax releases their short-focal-length Pancake.
--Mark
