In terms of utility, AF lenses enable autofocus, and MF lenses do not. For carefully-composed images, you may not miss the AF. If you're out in the fields chasing insects, AF may enable you to get shots that you would otherwise miss.
In terms of magnification, here's a quick table: SMC-A 50mm F2.8 Macro: 0.5x SMC-A 100mm F2.8 Macro: 1.0x SMC-A 100mm F4.0 Macro: 0.5x SMC-A* 200mm F4.0 Macro: 1.0x The Pentax SMC-A* 200mm F4.0 Macro is compatible with the A2X-L teleconverter to yield a 400mm F8.0 that gives 2.0x maximum magnification. I bought my A* 200 a couple of years ago from B&H for $950. The FA* 200mm F4 Macro goes for $1350 at B&H. That's quite a price hike! --Mark - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
