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01-12-2012, 07:57 PM   #16
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I have the original unimproved 18-55, and the 16-45. They're both relatively poor wide open; they're both better stopped down. There's not much difference between them, although the 16-45 doesn't have as much light fall-off in the corners. That's on a 6mp camera. The results from both lenses are worse on my 10mp camera, because 100% at 10mp is a lot more (potentially) detailed than 100% at 6mp. Based just on pixel count, I'm guessing that on a K5, almost any lens would look pretty terrible. As cameras get more megapixels, it's become easier and easier to see lens flaws.

Regarding copy variation, I've had defective Pentax DA and other lenses, but generally they've been defective in that they've had significantly different performance across the frame, probably due to an assembly error (decentering, etc.) I'm not sure it's as likely that, outside of focusing issues, you'd get a lens that was just uniformly bad across the frame. I have no indication in that sense that my 16-45 is "bad", I just don't find its performance much different from the 18-55. With all my lenses I find the results less than pleasing at wider than about f8, and I've developed more affection for f11. Back in the film days, it seemed like results from my Takumar and Canon FD lenses held up better at slightly wider apertures, but I don't have scientific data to back that up.

Paul

01-12-2012, 08:28 PM   #17
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No offence tibbits, but your 16-45 must be broken. My 16-45 is sharper across the frame than my DA 15mm, which is what Photozone shows too. Also higher resolution than the DA 21mm (they measured at 24mm}.

You can have a look at full size samples of my 16-45 and 15mm here:

https://picasaweb.google.com/100586096103361553535/Comparo?authkey=Gv1sRgCLOD9LjmoOKTlAE#
01-12-2012, 09:22 PM   #18
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QuoteOriginally posted by audiobomber Quote
No offence tibbits, but your 16-45 must be broken. My 16-45 is sharper across the frame than my DA 15mm, which is what Photozone shows too. Also higher resolution than the DA 21mm (they measured at 24mm}.
Ditto. It's rather strange that the DA16-45 is sharper than the prime DA14/15.
01-12-2012, 09:43 PM   #19
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QuoteOriginally posted by wlachan Quote
Ditto. It's rather strange that the DA16-45 is sharper than the prime DA14/15.
Nope, check Photozone results for confirmation. The 15mm is sharp in the center and has remarkable contrast. It also wins hands down for distortion, CA and flare. Resolution across the frame is not a strength.

Anyway, tibbits was comparing to the 18-55 and not seeing a difference.That's just not right.


Last edited by audiobomber; 01-13-2012 at 06:24 AM.
01-12-2012, 09:57 PM   #20
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That's what I mean. Both DA14 & DA15 have decent centre sharpness but weak on edge/corners. The DA16-45 is rather flat field and has decent sharpness across the frame. One would think modern primes would do better. Pentax is just full of surprises.
01-13-2012, 06:27 PM   #21
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Something that has always amazed me about the 16-45 is that the front element assembly is only very loosely attached to the rest of the lens, and yet I've done pretty detailed testing, and shifting that front assembly from one extreme to the other (left/right, up/down) produces no change in sharpness. But my lens has been that way from the beginning so I don't think it's defective. And it's very consistent from side to side and corner to corner, which is completely different than the actually defective DA and other lenses that I've owned, which, for example, would focus differently (or not at all) on one side of the frame vs. the other.

My experience has been that results from both the 18-55 or 16-45 are a little uninspiring, at least in the corners, until you get down to f9.5-11, and then they're both pretty good, at least in a 6/10mpixel world.

Paul

Last edited by tibbitts; 01-13-2012 at 06:35 PM.
01-13-2012, 06:34 PM   #22
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QuoteOriginally posted by tibbitts Quote
Something that has always amazed me about the 16-45 is that the front element assembly is only very loosely attached to the rest of the lens, and yet I've done pretty detailed testing, and shifting that front assembly from one extreme to the other (left/right, up/down)

Paul
Maybe worth sending in for a look. I think Pentax Canada charges around $130.00, and they quote first. I'm a big fan of the 16-45, but I have to admit, the build quality could be a lot better.

Last edited by audiobomber; 01-13-2012 at 06:56 PM.
01-14-2012, 09:36 PM   #23
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QuoteOriginally posted by focus Quote
All, shots i took were handheld. I dont have any shots to show as yet. I agree, f8 did seem to be best of the lot, however i went through a lot of different apertures from f4 - f 13, couldnt see any great difference in the lenses. also ive read reviews were owners of the 16-45mm have thought it aslo served as a great macro lens? - i find this incredible to believe with my version of this lens, but I primarily, bought this lens as a landscape lens, also hoping it would serve as a general walk around one as well. Am i expecting too much from the 16-45mm? should it be the better lens of the two? - thanks -mary.

Try looking at the corners with the lens wide open. You'll notice that there is almost no vignetting, compared to the kit lens.

It's not a macro lens, but you can focus close with it. IIRC, the minimum focusing distance is about 9 inches. That's from the sensor plane, not the front of the lens.

It's my favorite lens, and I take about 90% of my pictures with it.

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