18-135 has been slaughtered by Photozone

http://www.photozone.de/pentax/597-pentax_18135_3556

To summarise, the performance at 85mm and above was so bad they actually sent it to Pentax service to be checked over - and were told that it was performing properly. Needless to say the Other Forum now has a two page thread saying how inept Photozone is, but personally the 18-135 is now off my list of potential travel options.

Scored one and a half stars (I think)
I wonder if it's anything to do with the K-5 sensor
having more pixels, although they tested the 35mm f/2.4
on the K-5 and that was OK

It comes down to the price as far as the review is concerned. it also looked like they where really excited about the lens before the test...

Unfortunately the negativity isn't just based on price, optical results seem pretty unimpressive, at least in the corners - the suggestion is that the 18-250 outperforms it and the DA17-70 definitely does.

The initial review by Pentaxforums wasn't exactly overflowing with enthusiasm and this seems to give an indication as to why - having said that several owners on here are happy with its performance so perhaps the review is overly negative, the Photozone conclusion has definitely made my mind up about the DA17-70 though, I'm keeping it!!

Simon

basically they're saying it offers mediocre optical performance, at a high price.

but it is well built, weather sealed and quiet.

if the image quality meets (anybody care to check?) the 18-55 then maybe it isn't so bad image quality wise, just over priced...

I don't know.... this is the first review I've read...

The other forum seem quite impressed with it if that means anything.

It shouldn't do: if I understand it rightly, having a higher resolution sensor increases the maximum result which can be measured but does not decrease anything. For example if they were to retest the FA43 with the K5, then its measured centre resolution at f4 would be higher (because it exceeded the measuring capabilities of the K10D sensor) but the measured centre resolution at f1.9 would be the same (because it was within the resolution of the K10D).

Someone on the Other Forum said (I haven't checked myself) that the corner resolution results for the 18-135 were less than those in Photozone's review of the 50-200.

here is something interesting:
link vs link

considering it is the same lens.... the Pentax score lower for image quality, but better for build quality.

says something to me about the accuracy of thier testing...
I have the old Pentax 28-200 and it was a rebadged version of the tamron (gen 1 28-200)... as I recall the Pentax version focussed a little closer than the tamron and had noticeably better flare and aberration control.

I think maybe their testing standards are somewhat questionable...

Whenever you put a lens on a higher resolution sensor, you always get an improvement over the lower resolution sensor. Depending on the lens, the improvement might not be large, but it will be there. Saying that a sensor over resolve a lens is a misconception invented by people with bad optics knowledge.

Oops, Pentax

Any chance that this mit be a front or back focus issue?

Slaughtered, hung, drawn and quartered... then dragged through the streets more like lol. Looks like pentax are better with primes

I'm pretty disappointed with the results as I was planning to get an 18-135 myself. Think i'll get the 50-200mm wr to complement my 18-55 wr to save a little money, though changing lenses will be a hassle i guess.




doubt it as the test lens was checked by pentax germany.

Just mentioned in another thread, two bodies are better than changing glass.

I have a Bigma 50-500 and it's actually a fine lens. However, I feel it's an exception as personally I'm not a fan of large range zooms. Modern lens design may be good but long range zooms are a compromise and more often than not, slow.

The 18-55 & 50-200 on two bodies is a win win combination.

Best regards

I await JR's findings with the lens. I'd be more inclined to believe him.....
I'm think Gerri might like this lens for weddings... it is certainly more affordable the the 50-135....

Someone in Pentax Germany's going to get fired! LOL