Here are some full size K10D JPEGS (converted from Raw) of boring,
but useful, brick wall shots of the DA14, DA 12-24 @ 12mm & 24mm
and the DA 16-45 @ 16mm & 28mm. All were shot at f4.0.
F/4 is not the optimum sharpness point for any of these lenses, Richard. The DA14 plateaus at f/5-5.6, the DA12-24 peaks at f/8 as does the DA16-45.
I wrote a fairly exhaustive review on the DA14 to the PDML recently:
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Anyone made at least a semi serious side-by-side DA 14 v DA 12-24(at
14) image comparison?
I recently looked at a couple of DA12-24 RAW demo files. There
weren't any that were captures at exactly 14mm. My prior impressions
that it is a good lens but has more CA and more rectilinear
distortion than the DA14 does at lens openings and focal lengths
which bracket the DA14 were borne out. The f/8 exposures were
significant improvements over the f/4 exposures. But I don't own one
so I can't do an exhaustive side-by-side unless someone wants to loan
me one for testing.
But those test shots inspired me to do some more exhaustive DA14 test
shots on a variety of targets. My summary:
- Some corner/edge light falloff is apparent until about f/5.
- Rendering characteristics vary depending upon focus setting and lens
opening, most are excellent particularly at f/4.5 and smaller lens openings
if working in the very near range.
- Corner and edge sharpness are satisfactory wide open but improve
greatly when stopped down to f/5-5.6, after which they continue to
improve a little but very slowly to f/11 or so.
- Much after f/11, diffraction effects begin to intrude on sharpness.
- Flare resistance is excellent even wide open.
- There is a small amount of CA, consistent at all lens openings,
which can be removed easily in Lightroom or Camera Raw.
- It is a demanding lens to focus critically when wide open and
focusing near the close-focus limits. At f/5.6 the DoF at normal shooting
distances is so great that it covers a multitude of sins, but wide open and at
close range you have to have it on the money. I go to manual focus and use
Pentax Magnifier FB 2x for critical focus.
- Using a tripod with this wide a lens is essential to getting the
best resolution. Moving to the K10D, the incremental resolution
upgrade is most advantageous for this lens and the DA21 Limited.
I've had the DA14 since I first bought the DS body and it is one of my most consistent performers. I've made well over 3000 exposures with it. The more I use it, the more I learn to exploit it, the more
I like it.
Compared to the Sigma 14mm f/2.8 and Canon EF14/2.8L that I tested, the DA14 is a jewel and incredibly inexpensive for its quality. Regards field of view coverage, comparing what I get from it against my old work done with Nikkor 20mm f/3.5 AI-S, Zeiss Biogon 21/3.5, and Leica Elmarit-M 21/2.8 ASPH lenses, it holds its own very well. It's not quite up to what I could get from the Hasselblad 903SWC's Biogon 38mm f/4.5 ... but then very very few lenses in this class are.
BTW: set to Program mode and the MTF line, the camera tends to keep it at f/5.6 most of the time, which is right in line with my evaluations which indicated best performance between f/4.5 and f/5.6.
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The DA 14 never seems to get as sharp as the DA 12-24 f stop for f
stop. I personally wouldn't consider one myself, the DA 12-24 is
more useful on all counts except for the extra stop.
Based on what I've seen in photos, including the ones you posted, I disagree. I had the 16-45 and found it an excellent lens but the DA14 was a better performer on sharpness and far better on rectilinear correction. I don't have a DA12-24 to do the same kind of exhaustive testing with that I put to the DA14 ... someone offers me one, and I'll do it.
But I find the DA14 to be an excellent performer, very useful and very flexible. I use it an awful lot for an ultrawide and get excellent results with it. And I'm pretty demanding...
G
