[normhead]

Rarely does a long zoom range excel optically at very wide or extended telephoto points, imho.

And what lenses were used to form this opinion? That's critical information to understanding the value of the point.

I use the DA 20-40Ltd zoom a lot! Totally like it! FWIW; I heard the 18~135mm is less sharp compared to the 28~105mm.

The outstanding feature of the 28-105 is outstanding 3D looking rendition.
But I can probably take some comparison shots and you won't know which is which.
Sharpness is vastly over-rated.

Owning both, the 18-135 is "the" K-3 lens, the 28-105 is "the" K-1 lens. Because of the different features in those cameras, I normally wouldn't be using both for the same shot. SO comparative sharpness isn't an issue. The issue for me is that for macro, wildlife and general use, the K-3 with an 18-135 is a much more versatile system, and will produce more subject resolution on flowers etc than the 28-105 on a K-1. The 28-105 on the K-1 is a superb landscape lens, but not so good at macro and birds and wildlife. The only way you buy a 28-105 for a K-3 is, you don't shoot lower than 28mm and you don't shoot over 105mm. As far as available zooms go, on APS-c it's pretty limited. On FF, it's all there is in a variable aperture zoom.

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Last edited by normhead; 02-26-2018 at 07:02 PM.

[acoufap]

If you don't do wide, the 28-105 is for you. My wife uses it on her K-5 and loves it. It's become her favourite zoom, I may have to buy her one of her own, because it's my only walk around lens for the K-1 and she often wants it when I want it.

Here's a question though, are you thinking of keeping the K-3 after you buy the K-1. I use the K-3 for action, wildlife and macro, and with the 18-135 it's great walk around combo for day hikes etc. too. I'd only buy the 18-135 if you plan to keep the K-3. Especially since the 50-135 was good enough for you on a K-30, so it's questionable how often you'd use the 18-50 end in any case.

The DFA 28-105 is nothing like the DA 18-135. It has less range and better IQ. There are times I leave the K-1 home and take the K-3 just because the DA 18-135 is so versatile. There are times I take the 28-105 and leave the K-3 home for the increases dynamic range and IQ, although in the real world, the IQ is pretty comparable between the two systems. IF I'd have to take two lenses for the K-1 to match the range of the 18-135, the longest being 200mm, that would make the walk a lot less enjoyable.

But overall, sounds to me like you just need the 28-105. Anyone who can get along with a 50-135 on APS-c can get along with a 28-105. But you're losing the ƒ2.8 if that was part of the appeal of the 50-135.

The bad part about that is when you go to a K-1 you need the DFA* 70-200 to get the same field of view and f-stop. Now you are talking some major size differences in equipment to get the same thing. I still mostly use APS-c for telephoto situations. And there simply is nothing like the DA 18-135 on FF for the K-1 as a walkaround lens. The 135 end on your 50-135 is now 200mm for the same field of view. There is no easy way to get that on FF.

I also own the DA18-135 and DFA28-105.

The DA18-135 for me was definitely a no go on the K-1. The worst of the DA lenses to use in K-1 FF or Square mode. So I had to buy the DFA28-105 - a great lens. I‘d support what normhead says.

A totally different setup would be a DA20-40 plus DA55-300PLM. The DA55-300PLM IMO has better IQ than the DA18-135 in it‘s FL range and is a little faster with quick silent autofocus. It has a wider image circle. So it‘s better usable in K-1 FF / Square Mode if interested to use it at the K-1. I use it a lot in all modes (FF, Square, APSC). In FF mode you mostly have to do some cropping. So shooting raw would be helpful. In addition besides the much longer max FL, which is helpful for compressed views, it‘s better concerning near distance shooting. Since I tested the DA20-40 some years ago I know it‘s also a pretty good lens with great haptic. But I guess I‘m waiting for a new DFA 20, 18-35 or 20-40 lens.

[SpartanD63]

I'm glad to see so many opinions here. I think I've decided on the 18-135.

The big thing is that when I get the K-1 down the road, I may as well save up and spend the extra for the 2.8 zooms or something like that. It wouldn't be a walkaround, carry everywhere camera (I plan to keep the K-3 for that) so the size and weight wouldn't be an issue.

And for a lens to use on a rainy day, the extra range and not having to change lenses is a major plus. When conditions are better, I've already got a few non-WR lenses that will give me better IQ when conditions support it.


Plus, it's half the money, and I can use the leftover to save for other gear

[Paul the Sunman]

I don't think you'll be disappointed with the 18-135. It's a nice all-purpose lens.

[Kozlok]

The 18-135 is available used quite cheaply, and has a great reliability reputation, so a reasonable used buy.

[jeffdrew]

And what lenses were used to form this opinion? That's critical information to understanding the value of the point.



The outstanding feature of the 28-105 is outstanding 3D looking rendition.
But I can probably take some comparison shots and you won't know which is which.
Sharpness is vastly over-rated.

Owning both, the 18-135 is "the" K-3 lens, the 28-105 is "the" K-1 lens. Because of the different features in those cameras, I normally wouldn't be using both for the same shot. SO comparative sharpness isn't an issue. The issue for me is that for macro, wildlife and general use, the K-3 with an 18-135 is a much more versatile system, and will produce more subject resolution on flowers etc than the 28-105 on a K-1. The 28-105 on the K-1 is a superb landscape lens, but not so good at macro and birds and wildlife. The only way you buy a 28-105 for a K-3 is, you don't shoot lower than 28mm and you don't shoot over 105mm. As far as available zooms go, on APS-c it's pretty limited. On FF, it's all there is in a variable aperture zoom.

I based my general comment on long zoom range quality on the dozens of related reviews in the forum database and my past multi-decade use of several Pentax/Tamron/Sigma analog zooms that are now used on my K200d & K3II. I don’t use the 18~135 mm because I made other choices. I am NOT disparaging the overall wisdom of purchasing any lens because the decision and use are all subjective. For me, the newer Pentax technology and DA*/DFA lenses are great! If the output rocks your world, then it’s a good choice! :-)

[normhead]

I based my general comment on long zoom range quality on the dozens of related reviews in the forum database and my past multi-decade use of several Pentax/Tamron/Sigma analog zooms that are now used on my K200d & K3II. I don’t use the 18~135 mm because I made other choices. I am NOT disparaging the overall wisdom of purchasing any lens because the decision and use are all subjective. For me, the newer Pentax technology and DA*/DFA lenses are great! If the output rocks your world, then it’s a good choice! :-)

You mean, you don't use an 18-135 because you didn't buy one, or you bought one and never choose it? trying to understand if you actually owned the lens and ditched it, or got turned off by the reviews and didn't buy it.

Sounds like you just didn't buy it. That's different type of knowledge. You know what people think about the lens. Who is the 18-135 good for? IMHO opinion, people who want excellent quality through the zoom range and who are really active and don't want to waste time with lens changes. People who want shots taken while enjoying other activities. It's probably the last lens built to the old Pentax standard "Lenses for the way people take pictures, not for the test charts." I can always carry my 21 ltd. 40 xs and 100 macro for special occasions, or my DA*60250 if I want edge to edge sharp across the telephoto range.. To me a zoom is what you use, when you don't have time for lens changes, or when the necessary field of view is changing as you shoot. My big disappointment with the K-1 is, there is no 18-135 equivalent with anywhere near the quality.

It is interesting to meet an older user with decades of use, who never bought into the Pentax design philosophy. Although I have to say, the new Pentax designed lenses are exceptional. But they cost a lot.

The 18-135 produces images as good as any lens, but it has a learning curve. You have to use it to it's strength. The 28 to 105 just seems good every where. But it's not as versatile and it cost twice as much. I like having both.

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Last edited by normhead; 03-02-2018 at 07:55 AM.