[john mood]

99% of the time my K-5 is attached to a DFA 100WR which is one of the finest lens I've ever used. It is so sharp with awesome DOF, that I hate to use anything else. But, now and again I need to have a wider view to shoot medium distance shots, i.e. bushes,
trees, agricultural fields, equipment. So I bought the highly recommended DA* 16-50mmF2.8ED. Well, basically I hate the lens. Its sharpness cannot compare to the 100mm, it is too heavy, and just doesn't meet my need for crisp, clean shots that are super sharp. So it needs to find a new home. But, what digital, autofocus lens will match the 100mm ratings? I considered the 31mm which people rave about, but it goes only to f22 and some of the shots I've seen don't meet the "feel" I want from my shots. Don't need all this bokeh stuff. Woud a DFA 50mm give me the breath I need? Zooms are nice, but not necessary in my work.

All recommendations welcome.

[dgaies]

Maybe a DA35/2.8 macro or the DA40? They're both very sharp and I would say have comparable output to the 100WR. I don't know if either goes above f/22, but in all honesty, shooting with such a tiny aperture is going to reduce the sharpness of your images (due to diffraction) anyway.

The DFA50 (or FA50) are also excellent lenses optically, but I think either the 35 or 40 might be a better pairing with the 100WR.

[FrancisK7]

DFA 100mm certainly appears to be a majestic lens. I've seen many shots of it a year ago when I was shopping for a macro lens. I ended up getting the DA35/2.8 instead because the focal length was more useful to me as I do a lot of portraiture as well.

I'm surprised you like 100mm as an everyday walkaround lens, I find it quite long, especially for an ASP-C sensor. For macro work, definitely useful... but day to day? To each their own.

The FA77 will definitely top IQ/sharpness, but it is not that much shorter.
DA*55 could please you
DA35/2.8, which I own, is very sharp. Couldn't tell you how much or less sharper than the 100mm. Probably less.
I won`t suggest the FA43 if you didn't like the FA31. They're similar.
DA*50-135 is tack sharp at F4 and up, superb IQ, super silent, but very big. You said the DA*16-50 was too big, so again, you might not like it

I'm afraid these are your only options for AF glass that matches your sharpness requirements.

I own the DA*50-135, DA35/2.8, FA77/1.8 and my unconditional go-to lens when I want spacetime-rift-inducing sharpness is the FA77 at something like F/2 and up.

[hcc]

I am surpised that the FA31mm does not fulfill your needs. Have you tried it or is it only a feel?

To shoot medium distance shots, i.e. bushes and landscape, I found the FA31mm my most polyvalent lens. The focal length is just right: not to wide, not too narrow. In addiiion the IQ is outstanding. You may not like the FA31mm IQ but it would be a very personal matter.

If you want a really sharp lens (sharper than FA31mm), I could recommend the Voigtlander Nokton 58mm f1.4. I bought the lens for outdoor photography. Initially for low light condititions. I found that the VL58mm is particularly outstanding in poor lighting incl. fogg, smoke, haze as well as low light (sunset, sunrise). The VL58mm is really sharp and I rate its IQ almost par with the FA31mm. I tend to prefer generally the FA31mm IQ but the VL58mm can be really astonishing.

Hope that the comment may help.

[FrancisK7]

I could recommend the Voigtlander Nokton 58mm f1.4. I bought the lens for outdoor photography. Initially for low light condititions. I found that the VL58mm is particularly outstanding in poor lighting incl. fogg, smoke, haze as well as low light (sunset, sunrise). The VL58mm is really sharp and I rate its IQ almost par with the FA31mm. I tend to prefer generally the FA31mm IQ but the VL58mm can be really astonishing.:

I took your advice in my thread and sent Stephen an e-mail. I'm getting one. Hope I like it

For the OP, though, it's no good because he wants AF.

[northcoastgreg]

I considered the 31mm which people rave about, but it goes only to f22 and some of the shots I've seen don't meet the "feel" I want from my shots

I don't quite understand why you want to go past f22, especially if you're concerned about sharpness. In any case, most non-macro lenses don't go past f22. (Although the DA 18-55 goes to f38!)

I don't think you can go wrong with any of the FA or DA limiteds, or the DA* 55. They are all very sharp and will out perform the DA 16-50.

[Ash]

I have an f/40 shot with the DA 18-55 - it can only reach that aperture at 55mm.
Definitely nothing to rave about. Flat and lifeless results.
Anyway, the limited series lenses won't disappoint you, given your current satisfaction with a 100mm prime lens.
Enjoy choosing.

[interested_observer]

Evening, I am certainly not going to defend the 15-50 at all. However, in general - you are going to suffer the reverse of what I went through. You are starting rather long and then going wider. In this respect you are going to suffer some "lack of sharpness", just due to the enlarging of the angle of view of the lens, along with going from a prime to a zoom.

The sensor size is going to remain constant (it does not change size, resolution or density when you change lenses), and the 100mm lens has a field of view of 16 degrees. In comparison, the 16-50 has a field of view that ranges from 83 to 31 degrees wide (in width). What that means is that each pixel at 50mm will be representing at least four times as much area when compared to the 100mm lens. Sharpness will degrade solely for this reason alone. This is just the law of optics. So you are going to need to factor this into your analysis of the lens.

Also, you are comparing a prime to a zoom. Just by the nature of the optical design, there are going to be compromises in the design of the zoom that the prime will not need to contend with. Very few zooms are able to match a prime in sharpness, especially a highly rated prime such as your 100mm.

The FA 31 is excellent. I also believe that the 43 is extremely sharp also. It would certainly be easier to compare a prime to a prime.

[calsan]

The DA 35 limited is usable at f22, but mainly if the subject VERY well lit and I would only use aperture for macros. Excellent at 2.8 through to f16 - I use about f3.2 though 5.6 mostly. I love this lens and it's as close to flawless as a lens could be in this focal length.

I consider 100mm to be a telescope on APS camera and have trouble composing at this length. In your case, I think it will take you some time to get used to even 35mm field of view - perhaps this is why you're not happy with the 16-50 - it's relatively hard to isolate a subject unless you get close??

The sharpness, however, will be there with any wide angle lens if you're shooting at say, f5.6 through f8. I even like my 18-55 in this aperture range.
I would recommend checking out the DA35 limited (two thumbs up) or the DA21 limited (which approximates the widest focal length of a point and shoot). The 15 may be too wide for your liking?

[dms]

If you are so concerned with getting enormous depth of field (is that why you speak of greater than f22?) you will be doing zone focusing and using hyperfocal distance--and I suggest a used older screw mount 28mm f3.5 or a 35mm f3.5. For low cost you will have an outstanding lens.

BTW at f/16 (on a Pentax dslr) a 28mm lens will be in satisfactory focus from about 1 meter to infinity (if focus distance set at 2 meter), and the values are about 2 meter to infinity (if focus distance is 4 meter) for a 35 mm lens. Isn't this enough?

[dms]

Sorry, I did not mean to limit it to screw mount. A K mount f3.5 28mm or 35 mm is equally good (although I find screw mount easier to use with zone focusing and auto exposure) and will not require a Pentax K mount adapter.

[john mood]

Thanks all. Good comments. After searching the options based on recommendations and comments, I am considering a DA 40 Limited which has great ratings in the reviews and a equally great price, about half that of the 31mm. Having used my old SMC M50 with the K-5 in trials, 40mm should give me the breath I need and should be a good companion to the 100mm. To answer the why of a near-permanent mouinted 100mm--I'm a botanist whose shots are 95% flowers or plant parts and the residual, ecology or landscape with the ocassional human.
Cheers.

[Bestzoom]

Hi John,
Have you given any thoughts to Sigma 30 f1.4 with a thread on this forum?

Cheers!

[DaveHolmes]

DA35 Ltd or DA*55 appear to be the 2 sharpest 'normal' lenses available by Pentax

[crewl1]

Based on your usage I say skip the DA40 and go for the 35 LTD Macro instead.