Have you considered the Tamron 90mm AF 2.8 macro? It comes in slightly better than the Pentax 100 as far as image quality, according to online numbers.
http://www.photozone.de/Reviews/Pentax%20Lens%20Tests/362-tamron-af-90mm-f28...-macro-pentax-
About the same price ($350 to $450 before $90 rebate through March xx). Gets down to 1:1. Tamron is slightly heavier (405) than the Pentax 100 (345), and longer (97) than the Pentax (81).
Originally posted by nostatic I primarily shot with a Nikkor 105mm micro lens, as I'm into macro, but also found it to be an excellent all around lens, although a bit long in tight spaces (not surprisingly).
You are referring to physical size of the lens? The Tamron's shell sticks out quite a bit beyond the glass, so you can probably get along without using a hood or a plain glass protection "filter".
Originally posted by nostatic Anywho, I'm pondering either the 50mm or 100mm macro. I have to say I wasn't crazy about the really narrow dof with the Nikkor as I usually like to get up close and personal, but it was nice to be able to work a little further away.
My understanding is that DOF is strictly a result of the image size and the f stop, regardless of what lens(es) you are using. So a 50 or a 105 or a 90, at the same (real) f stop is going to give you exactly the same DOF as long as the dragonfly is the same size in your viewfinder.
A slightly more tele lens (90 - 105) is going to give you more working distance than a 50, of course. But it'll also let you pick your [out of focus] background better than a 50 would.