Due to the very good reviews I've bought the 100 SMC D FA and not looked back. The lens is extremely well finished, very bright, and the autofocus quickly and accurately. The images are very sharp even at full aperture, this increases with a slight dimming yet. Works just as fast at the K5 to the K10. It is very advantageous that the fine piece is waterproof. Since then it may have a little time to rain, if you're in botany on images hunting. After very intensive use I can find no disadvantages - it would buy again at any time.
