

Here is a new poll I think to raise. Both lenses are great optically (provided that you get a good copy nowadays for those units AIV (produced in Vietnam)!) and both are actually still in production.
The A50 is half-stop faster but it is just an old MF lens. And on APS-C, its f/1.2 aperture will provide shallower DoF that could be closer to that of a 85/1.4 on 135 Full Frame. The DA*55 is a bit slower but it has AF. It uses SDM, though, which is infamous in accuracy, speed and reliability. The DA*55's focusing throw is long and is no different from a MF lens actually. Furthermore, after the SDM is dead eventually or suddenly, the DA* will be no difference from a MF lens! ;-D
Do note that Pentax/Hoya has never officially suggested that the DA*55/1.4 is anything that is designed for Full Frame (against what I have been suggesting them that they *should* make it clear and then *everyone* will win, since years ago!). In fact, I suspected that the lens hood of the DA* is just incompatible on Full Frame, although as for the lens it seems to be working on FF cameras without any problem.
Both lenses could produce quite good Image Quality on APS-C when just stopped down to f/2 and the bokeh will not be bad (depending on your requirements or simply preference!). The DA* is easier to buy and the A50 maybe available only in US grey market or you need to order it directly from Japanese online shops, like at the Mapcamera. The prices are close enough for both, provided that you can find it!
So, here is the *tough* choice! If you just want to buy a better 50ish now in Pentaxland, what will you choose? I mean genuine Pentax! Not a Sigma or else. Btw, the Carl Zeiss ZK 50 has been discontinued.. Okay, let's go!
Last but not least, whilst all Pentaxians are encouraged to participate in the Poll, which each vote is made anonymously, I encourage even more that you could reply back and post a "Comment" for the rationale and reasons of yours behind for making your choice - There would be some good food for thought and it is always interesting to see for more opinions and viewpoints of what others think! :-)
Related:-
The Very Different Fates of Two ex-AOC Top Optical Engineers
50mm Lens Shootouts
Compatibility of DA Lenses on Full Frame
A50/1.2 is Now Made ("Assembled") In Vietnam
Where are the Pentax DSLRs and Lenses Made?
FA 31 Limited: Assembled in Vietnam Vs Made in Japan - Case Studies (Part 1)
FA Limiteds: Made in Japan Vs Assembled in Vietnam - Continued (Part 2)
Alex · 753 weeks ago
frank d · 753 weeks ago
Fortytwo · 753 weeks ago
RiceHigh 110p · 753 weeks ago
rhermans · 753 weeks ago
I've got a smc 50 f1.7 and I on very very small occasions use it at 1.7. , almost always stop it down. So a 1.2 vs 1.4 doesn't make that much of a difference.
The only reason fot the DA*55 would be the AF as good or bad as it is, you can always MF if it doesn't do the trick.
Just My 5c
RiceHigh 110p · 753 weeks ago
Match · 753 weeks ago
RiceHigh 110p · 753 weeks ago
quatrecouleurs · 753 weeks ago
RiceHigh 110p · 753 weeks ago
Zebooka · 753 weeks ago
It has smoother bokeh, while DA* 55/1.4 gets sharper image but with MUCH more spherochomatism (and this ruins final image).
Also DA* is SDM - no way.
RiceHigh 110p · 753 weeks ago
YoukY63 · 753 weeks ago
A50 f/1.2 is only 1/3 stop faster than 55mm f/1.4, not 1/2 stop. Also, a 50mm f/1.2 will be far from a 85mm f/1.4 on FF, it is the exact equivalent of a 75mm f/1.8, so let's say roughly a 85mm f/2!
Then, 55m is longer, and a quick calculation in DOF master say show that there will not be that much difference in the result of these both lenses (for a focus at 2m, near and far limit of focus is 4cm from focus point for each lenses).
By the way, even if you don't like SDM AF, at least it will be more accurate wide open than your eyes through the little viewfinder in manual focus.
So no brainer: DA* 55mm (even if I prefer the look of the A*50mm ;-) )
RiceHigh 110p · 753 weeks ago
As for the DoF, you will get the same effect with the same AoV (Angle of View) *and* the same effective lens diameter size. Well, we all know that 50 and 55 have a 5mm difference. But if you had to calculate and compare, only the 55 is close to a film 85 (which is actually just equivalent to a 84.4mm on APS-C for its actual AoV) with an effective diameter of 39.3mm which is f/2.15 (but not f/2.0) of a 84.4mm lens on Full Frame, strictly speaking and to be precise.
Furthermore, the 50mm lens on an APS-C crop camera is equivalent to a 77mm lens, not a 75, if everything is to be more accurate.
Fortytwo · 753 weeks ago
I'd pick the A* 50/1.2 It's better build and probably will last longer than the DA*. Although I consider that to be an excellent lens too. In the end, I'd rather have a lens that stays in one piece than whatever advantage the DA* might have. There's no substitude for a full metal and glass construction...
david · 753 weeks ago
I have a focusing screen, and love the fact my K10d will tell me if I have it in focus.
Otherwise, I would buy the FA 50mm 1.4. The fact is whatever company you look at, their old film-derived 50mm are still the best, and have the best price point. Nikon added to their lens lineup with a G, and it was soft compared to their old lens. Oh, and talked with a Canonphile, and he said that their 1.2 50mm is crap.
quatrecouleurs · 753 weeks ago
Does anybody have an experience with a split image replacement focus screen ? I would like to buy one since long time now, but I'm not sure if it is really improving focusing over the in-camera focus confirmation... Especially shooting wide open !
david · 753 weeks ago
quatrecouleurs · 753 weeks ago
K10D focus confirmation for me does make too much errors (in low-light portraiture especially), and I can't see the focus plane position and moving in K10D and K-x viewfinders (like it finely enough in Nikon FM or perfectly in Mamiya RB67)...
david · 753 weeks ago
So far the results have been great. I just wish the screen worked in a K7 or K5, but they have different screens. Like bundling the IR remote with the camera, I think Pentax would be wise to include this style screen with their cameras compared to the glass they now include. You take a Kx and some mf lenses, and you are as clsoe to the size of the old compact SLRs as you can get.
quatrecouleurs · 753 weeks ago
RiceHigh 110p · 753 weeks ago
http://ricehigh.blogspot.com/2007/04/when-focusin...
http://ricehigh.blogspot.com/2009/01/when-focusin...
Heiko · 750 weeks ago
Because... ...I already went out and got one! a DA "star" 55 /1,4 SDM.
Yeah that's right! I inherited some really nice 50/1,7 smc-A lens from my father who "upgraded" to k200d plus kit-zoom 18-55.
I immediately began to love the low-light style of shooting and the extraordinary sharp and contrasty results I got from that cheapo old A-lens. It just had some odd flaw: the diaphragm wouldn't close beyond f/9, any longer!
So I made up my mind after the financial crisis dropped on Pentax-land resulting in a HUGE rise in the price-range of almost anything interesting they still sell when it comes to class. So I decided my next step would include learning about street/outdoor/people subjects which meant I needed something reasonably long and - ideally - wheather-resistend. Because "WR" was the very reason, I got my K20D in the first place (after I saw and liked what my father wrinched out of _his_ K200d).
No camera, regardless of sensor-technology progress, can yield better-than average results without some good glass. My DA55/1,4 thus became my first and only (till this day) all-weather capable lens.
It really was kind a "no-brainer" decision I made. I haven't used it as much, yet. But I am constantly thinking of places and try to visualize shots that will make this little baby shine. And for the rest of the time I simply swap it in front of my camera whenever there is a need for wheather-sealing and some good chance for the 55mm focal length to provide me with the right kind of image-angle at the moment.
Taking photographs with a prime lens really trains the eye! And being able to do that with the added peace of mind provided by WR in both: the body and lens; now this makes it a lot less paranoid for me, especially considering all that money I can shuffle out the window just to enjoy the tools _needed_ for all the shots I am willing to capture.
Maybe I'm a little late to the party. Those are my thoughts. Raw and Clear!
RiceHigh 110p · 750 weeks ago