Originally posted by john mood Thanks all. Good comments. After searching the options based on recommendations and comments, I am considering a DA 40 Limited which has great ratings in the reviews and a equally great price, about half that of the 31mm. Having used my old SMC M50 with the K-5 in trials, 40mm should give me the breath I need and should be a good companion to the 100mm. To answer the why of a near-permanent mouinted 100mm--I'm a botanist whose shots are 95% flowers or plant parts and the residual, ecology or landscape with the ocassional human.
Cheers.
Most of those lenses are not going to give you the flat field that you are used to with the 100 Macro. I've found that if I take a LOT of pics with my macros I look at the photos from my other lenses a bit differently aftertwards. I would suggest that you consider a 50 macro lens as it will compare most closely with what you are used to seeing from your 100Macro. I have both the M50 and M100 Macro and find the 100 more useful for most things macro but the 50 does give a wider field while keeping the sharpness of the 100. Just a thought. Good luck.