Originally posted by cport I have 70/2,4 ltd and FA 135/2,8. I like them, really - both are very small with fast AF, 70 ltd is amazing optically, but sometimes I have a feeling that I am not using them enough. I had got an idea that I can buy another lens instead of them. A natural choice is D FA 100/2,8 WR, which would add WR and macro options.
However, after reading PF reviews, many users complain to slow AF of 100/2,8 and aberation. Is it really so bad? Could somebody give me more experienced feedback? Does anyone have experience with the same lenses? How fast/slow is AF speed of 70/2,4 (resp 135/2,8) in comparison to the 100/2,8 WR?
The D FA 100 WR ist sharp and fairly well corrected, at least on par with the FA 135/2.8, according to what I've seen published from that lens (never had one). The bar is high for a macro lens which has been released in the not too distant past and Pentax maybe should have overhauled thr optics as well. It does show some coloration of out-of-focus foreground/background, esp. wide open with harsh contrasts, for very critical situations only. Otherwise it has very nice rendering - see the
lens club. Perspective is noticeably different from the 70mm.
Compared to the fast-focusing DA70/2.4, it has just slightly slower focus as long as you keep it in the 'distant' range. It takes a very long time to go through its entire range though. So if you lose focus, just lift up you finger/thumb (in case of back-button fokus) briefly and it will refocus without going all in and out. So with a bit of practice, I used it successfully for indoor sports for a while.
What you likely haven't considered yet: It's one of the best current lenses handling-wise, very compact and light, with a small diameter, which makes lighting setup in macro easy. The hood is superb, no other current macro has so usable scales, manual focus-throw and -feel. A world of a difference to the previous generation's (non-WR) full time manual implementation, on par with the DA70, just with a wide and comfortable focus ring.