Originally posted by sTi DSims, I am interested in your thoughts about the 43mm vs. 55/1.4. I have the 55 and really love it, but I am also interested in the 43. How would you compare especially the color rendering and bokeh of the two lenses? I am asking because from some 43 pictures I've seen I've got the feeling that the two lenses render very similar, and both seem to have very nice & smooth but somehow still "spicy" (I am struggling for words here...) bokeh. Or am I mistaken?
There's a simple breakdown I've given before. I think there are 3 outstanding ~50mm Pentax lenses, and here they are. The DA*55 is the only one I don't own (simply because I have trouble justifying owning all 3), but I've used it:
DA*55 - sharpest, especially near wide-open at f/1.6 or f/1.8. The FA*85 (and probably A*85) is its only peer in this regard, that can actually be this sharp and clear this fast. However, it can have terribly harsh backgrounds at times (such as with some bushes), while being beautifully smooth at other times. Color rendering is more or less like an average Tokina (which is good), but not the step-above that the FA43 is.
FA43 - Backgrounds are never that bad but never especially smooth either. In other words the background's not distracting, but may not be noticeably beautiful either. However, foreground colors are striking, beating the other two, as well as any other lens I've used. NOT optimally sharp unless stopped down a bit - preferably a whole stop or more. It is effectively 2 full stops slower than the DA*55, but still can't be beat in its overall rendering and colors, especially if you're stopping down a bit. This little silver finished metal lens and hood looks the coolest, correctly giving people the impression that - despite its small size - it could be something special.
A or K50/1.2 (I have the K version) - Almost impossible to get a harsh background - always smooth. Only the FA31 is similar in this regard. Doesn't appear that sharp throughout the first stop or more, but not bad either. I believe the K version has slightly nicer backgrounds and I prefer it, although some of this is caused by what are technically called flaws today. i still like it better. Color rendering is the beautiful warm rendering of an ~35 year old Pentax lens.
In summary, all 3 are distinctly different. I think you could easily own any 2 of them. If I were starting over and I could only own 1 I'd probably pick the DA*55, but as it is I can't bring myself to part with the unique qualities of either of the other two, especially since each qualifies as the "best Pentax lens made" in its particular area of strength.