In the close up range shorter than what the 105 mm normally focuses to (i.e. resorting to put tubes on the 105mm) I would expect the 100mm Macro to absolutely crush the 105 performance.
BUT, when used at the optimum working distance of the 105mm (I do not know the figure, 10 meters ? ) I would bet that the 100mm would have a hard time matching the performance of the 105 because the 100 is one of those pseudo zooms with many more elements than necessary for a general purpose application like the 105 is designed for....This has also been argued about a zillion times too. It is the prime vs zoom debate (sort of) and if you use a prime at its ideal conditons, they are usually pretty hard to match with a (pseudo)zoom at those same ( ideal for the prime) conditons... JCO -----Original Message----- From: Fred [mailto:[EMAIL PROTECTED] Sent: Saturday, November 13, 2004 9:30 AM To: [EMAIL PROTECTED] Subject: Re: A Question About Macro Lenses > Using the A100/2.8 macro and the K105/2.8 on the same subject, there > didn't seem to be any observable difference between the two photos. > Under what circumstances would a macro lens be the better choice, and > when might an ordinary lens be a better option? I really like the A 100/2.8 Macro a lot (one of my favorite lenses). I also used to own the K 105/2.8 (at the same time as I owned the A 100/2.8 Macro). I pack the 100/2.8 Macro for almost any outing, whereas I almost never packed the K 105/2.8. The 100/2.8 Macro let me shoot almost anything that I wanted (using a lens in the 100-ish range), close or far, while the K lens could not focus too close. The maximum apertures were the same. Bokeh (important to me) may not be the best feature of the 100/2.8 Macro, but it certainly is not for the 105/2.8, either. So, in answer to your question, Shel, specifically referring to these two lenses, I'd say that - for me - the A 100/2.8 Macro would ~always~ be the better choice - <g>. Fred
