http://www.photozone.de/pentax/597-pentax_18135_3556?start=1
It scores only 1.5 points out of a total of 5. And so does the price-to-performance ratio. :-o :-( The final verdict of Klaus is quoted as follows:-
"Verdict
We were quite enthusiastic about the Pentax DA-SMC 18-135mm f/3.5-5.6 ED AL [IF] WR at the time we received it. Regarding the high pricing of the lens we were expecting a very good performance throughout its broad zoom range and all that in a very compact, high quality body. Unfortunately the testing reality revealed a mediocre optical performance at best. A lens with a 7.5x zoom ratio may be quite ambitious but other manufacturers managed to design pretty good lenses with an even more extreme range. The Pentax lens is actually very good to even excellent in the image center but the borders/corners suffer from massive field curvature at the wide end and plain sofness at tele settings. This is certainly no issue for portraits and such but you don't really want use this lens for architecture or landscape photography here. This is also in so far surprising because the (cheaper) Pentax SMC-DA 18-250mm f/3.5-6.3 (a Tamron design) was actually very usable here. The secondary characteristics (distortions, vignetting, CAs) are about class-average. A very positive aspect is the build quality of the lens - the lens body is based on tightly assembled, high quality materials and the weather sealing is a quite unique selling point. The new DC AF motor may not be as fast as Pentax' SDM but it's quite fast and comparatively quiet. The biggest problem of the lens is its pricing which is simply not in line with the optical performance. Therefore: Avoid! Better consider the Pentax DA-SMC 17-70mm f/4 SDM instead which is a far better lens."
And, do see also this additional remark made by Klaus at the DPR forum. The reason for why the publish of this lens review is delayed has been talked about. The chance was given to Pentax but the lens was checked to be "within factory specs".
Previous Related Stories:-
PhotoZone DA 18-135 Test Results Will Not be Good (Very Possibly..)
Ned Bunnell's (Official) K-5 + DA 18-135 Samples
Saturday, April 16, 2011
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Comments by IntenseDebate
jose · 729 weeks ago
It is sadly a bad news for pentax users like me. I have a K200d and I don't know what new pentax buy.
I'm thinking about it and I probably go for a canon 5d mark II because it only cost over 600 Euros than the k5.
I'm very sad...
sigourney · 729 weeks ago
LMAO :))))))))))))))))))))))))
just have a look into Canon or Nikon counterparts...it wipes the floor with newest pentax zoom at half the price.
Guest · 729 weeks ago
What a waste. Pentax made some truly great 35mm lenses. I'm glad I bought a Sony NEX to use my old lenses on.
Sad to say, but Pentax is dead. Pentax was already competing on the cheap, but Hoya has raised prices and lowered quality. I'm glad I switched systems.
Chris · 729 weeks ago
1. On pricing: the lens is selling in Germany for 700 EUR (roughly 900 USD), however I got my copy at B&H for 500 USD. That relationship is typical for Pentax, and take into account that there is no (country) distributor involved like in other countries - Pentax is selling directly in Germany!
2. On quality: Although I prefer small prime lenses (the limiteds and the 100 WR) for their quality and elegance, I have purchased the 18-135 for its versatility in situations where lens changes are a no-go. There, the WR feature is a unique selling point, as Klaus also notes.
3. According to Klaus/Photozone, at 18mm, the barrel distortion of the 18-135 is -3,5%, of the 18-250 is -4,3%. Sharpness in the center is excellent for the 18-135, border is comparable with the 18-250.
4. For longer focal lengths, the 18-135 shows a strange behaviour with excellent sharpness in the center and mediocre values at the border. That may be ok if used in a portrait application, but certainly not for telephoto shots. I have just checked this and can confirm the problem.
Anyone wants to buy a not-very-much-used 18-135 in mint condition?
C
Chris · 729 weeks ago
Chris · 729 weeks ago
* barrel distortion can be corrected in PP or even in camera with a K-7 or K-5.
* the lens is nothing short of excellent in center sharpness. Border is pretty bad. But isn't the same thing true about the much-appreciated FA 77 limited with its "magic dust"?
Tomasz Worek · 728 weeks ago
The latest Pentax problems (poor performance of 18-135, K-r front-focus problem in tungsten light and stains on K-5 sensor) are really alarming. They released two really good cameras (K-r and K-5) and then ruined everything :(
Mage · 728 weeks ago
Slash · 690 weeks ago
Sadly though the optics were a bit crap to put it bluntly I could live with distortion that's expected but the borders are useless at the tele end.
After I bought the lens I borrowed a D7000 and 18-105mm VR off a pal, and boy does that lens thump the living daylights out of the Pentax, and it costs not a lot if bought in kit lens. So no WR and plastic mount but it "shames" the Pentax optics are great sharp at tack at all focal lengths wide open. Still has distortion but boy what a difference good optics v very mediocre
After that I sold the 18-135mm WR on ebay and I don't miss it one bit it's a pants lens at the best of times and very weak optics wise. I'd rather have good optics and cheap build sorry dudes that's life. This lens is an embarrassment to Pentax
RiceHigh 110p · 690 weeks ago
Slash · 689 weeks ago
Even Ned Bunnells shots were pretty awful and you'd have thought Pentax might have dug about for a better copy if they could get one.
The lens just isn't that good optics wise