Quote: Thank you for the detailed response. So if I get you correct, I can use the 18-135 at say 30mm and it'll be just as sharp and controlled like the 16-50 at 30mm?
The reason for the 16-50 is a waterside ƒ2.8, as afar a I can tell. By 30mm mm, the 18-135 at ƒ4, You need to let in twice as much light, to get to ƒ2.8, so the DA*16-50 needs to be quite a bit heavier and for DoF if you want it, the DA*16-50 is going to open wider and create more pleasing out of focus areas. There are advantages. But, landscape at ƒ5.6 or higher insn't one of them between maybe 22and 30. Personally I've stopped carrying my DA*35 2.4, because the DA 18-135 will give me the image I want, even thought the DA 35 is a very good lens. I'm sure the DA 35 will be marginally better pixel peeping, but as in my 50's example above, any differences will be insignificant. The 18-135 is two lenses, a very high end 18-50 and a centre sharp DA 60-135. Every one of the criticisms I've seen on the forum has been people comparing the 60-135 part of the lens to someone else's 16-50 or 17-50. That's just misrepresentation. And personally, I find it offensive, that after I've taken the time to correct this over and over again, people who support other lenses for this role, continue the malign the 18-135, and proposed other lenses that are no where near what it is at it's strongest.
The only lens I'd recommend over it based on the test charts would be the Tamron 17-50, and I have to put an asterisk on that because so many have had mechanical issues with that lens. I was already at the point of refusing to recommend it, when the AF on mine totally died. It's adjusted to +10 and still won't focus.
IN a way, it's not that the 18-135 is all that great, it's that the other offereings The Sigma 16-50, the Pentax 16-50 and the Tamron 17-50 are rated at the highest , an 8 put of 10.
DA* 16-50mm vs. Sigma and Tamron 17-50mm F2.8 Comparison Review - The Bottom Line | PentaxForums.com Reviews
The DA 18-135 rated at 8.4 is right behind the DA*35 2.4 rated at 8.5 and a half point ahead of any of the above 3.
The people who go on about these other lenses, putting down the 18-135 just shooting off their mouths without doing their home work. At this point there is just no excuse for that. Personally, I'm going to start ramping it up a bit when the OP asks for something top notch and people recommend inferior lenses for the described purpose. The question isn't "What lens did I buy, that I'll stick with no matter what?" The question is, "For the use described by the OP, what is the best lens?" These question turn into cheerleading sessions for one lens or the other.
Even in a football game half the cheerleaders are wrong every game, in that the team they cheer for isn't the best team that day.
There area pile of folks who post here who are nothing but cheerleaders for helens they bought, and absolutely no restraint recommending it over better lens. Accept no advice without supporting links or investigating the forum reviews and Photozone. That would be my advice. These guys who buy on helens and think they know everything, or who got a bad copy of a lens and continuously trash that lens, ignore them. Use multiple sources read what the forum reviews and protozone have to say, and look in the Lens Clubs both for images and for what people say about the lens, and you have a informed decision.
Some jackass saying crap like "the 18-135 is soft at the edges" don't even pay attention to the one liners. They clearly haven't done a stitch of research on the lens, and are just repeating nonsense posted by other posters.
Now if someone wants to make a coherent logical case stating some other people's research and testing, other than joe blow shooting off his mouth, I'll be happy to look at what you come up with. I'e got my case outlined above with relevant quotes. Bring it on.
I won't be holding my breath. I've been through the evidence enough times, to know, you have nothing.
My biggest regret is that the first time this trash was tossed out as advice I didn't create a comprehensive file I could just paste into every thread where it cam up , and create a bot to do it automatically. I have continually put the information out there, and people I can only describe as lazy have continued on about how weak the lens is, without actually looking at the tests and reviews.
Lazy, there's no other word to describe those attitudes.
At this point I'm almost certain there's going to be a few people come on and justify their bad advice. Not with reviews, not with test scores, not with side by side comparisons of images, but with a rehash of every poster who's contributed an untruth about this lens.