[bandarbalu]

Hi all,

I'm relatively new to the forum, and I've spent some time trying to answer my first question by digging through the history and linked review sites, but haven't gotten very far. I apologize in advance if this is an old topic and I just haven't been clever enough in my searching to find answers that help me.

I started the leap from four-thirds to Pentax with a K-5 IIs, and had ordered the 18-135 from Abe's of Maine as my starter lens, but the lens price was too good to be true (I couldn't tell if I would ever actually get a lens - it pays to read their customer service policies before you buy something from them). The current price for that lens on Amazon still seems to be mighty good, but since I've now committed to spending more than originally planned on my first lens, I'm widening my search.

My current kit is an Oly E-620 with a 14-54 most of the time, ZD 70-300, the Sigma 105mm f2.8 macro, a legacy Zuiko 50mm f1.8, and the 14-42 and 40-150 kit lenses. I also have a grab bag of hand-me-down legacy zooms and primes that I use very infrequently. My wife puts some miles on the E-620, and I even let my six-year-old mess around with it occasionally. The 14-54 is an outstanding lens, both in tests and in the real world - frankly, none of the four-thirds sensors can do it justice. For me, the most noticeable improvement over all my other lenses is its AF performance. The E-620's biggest weakness is AF (one of the big reasons I got the K5), but it actually became passable with the 14-54 (using center point only). I know the K5 is a way more capable camera than the E-620, and since I'm going to spend more money than originally planned on my first lens, I thought I'd dig a little deeper and see just how much performance I could buy.

$400-600 is the price range I had in mind, but those aren't absolute limits. The first lens has to be usable for my wife and preferably for my six-year-old on occasion, which pretty much limits it to an AF zoom. I've had great luck with used lenses (the 14-54, Sigma, and 50mm were all bought used), so that is definitely an option. AF and zoom are needs; my list of wants, in descending order, are: optical quality; weather-resistant; focus speed; quick-shift; and zoom range. I'm a little worried that I'll be disappointed if the first lens is inferior to the 14-54, even if it has extra bells and whistles, like WR and a bigger zoom range. I'd like to have something within the month, so I don't really want to troll the marketplaces forever looking for a lens that comes up once in a blue moon.

The 18-135 is definitely still in play, but the first lens to make me have second thoughts was the Sigma 17-70 macro when I read the review here and saw the price. No WR seems to be the drawback. Then I noticed that the other superzooms are in the same price range, and having shot with the Nikon 18-200 before, I started wondering if I hadn't researched enough to know if there was a lens approaching that quality in the lineup. AF speed would worry me about superzooms unless someone can vouch for them. On the top end of my price range, the DA* 16-50 appears to have a great price new at the moment, and it ticks almost all the boxes, but both the Pentax and Sigma 17-70 options seem to have outstanding optical quality, so it kind of begs the question whether WR and perhaps marginally better optical quality warrants twice the price. Then again, I might have gotten the lens characteristics totally wrong.

Oh, and by the way - I was lucky enough to get a hand-me-down Pentax ME body with a 50mm f2 lens just before I ordered the K5, so I've at least been able to test out the camera:

[jatrax]

For general use the 18-135 is quite good. In good light and stopped down a bit and avoiding the extremes, more than good enough. Certainly not the best available but consider to reach roughly the same focal length you would need the DA*16-50 and DA*50-135. Of course that is f/2.8 and far better optics but you see what I mean.

I would suggest getting the 18-135, it is a good all around general purpose lens that will have a place in your bag even if get other lenses later on.

[Merts]

I'd also recommend the 18-135. It covers a broad enough range that you can leave it on the camera as the default lens and it will do a pretty good job most of the time.
That's basically what I do with mine. I swap to other lenses as the need arises, but if I need to just grab the camera to capture a moment, it's the best bet.

The water proofing and quick-shift focus over-ride are both handy too.

[VoiceOfReason]

I've used my 18-135 to get some great shots and I've used it in the rain with no problems at all. I'd recommend it.

[voy-tech]

I recently switched from a m43 system (Panasonic G3 that I've used almost exclusively with Panasonic 20mm/1.7) to a K5IIs myself. I was debating between getting a Sigma 18-35 and the new Pentax Ltd. 20-40 and decided to pick up the Pentax and return it for Sigma if it turns out not as sharp as I would hope (note here: I mostly shoot landscapes so I was looking to use the lens mostly around f/8). I recently took the Pentax lens for a spin and I'm very happy with the results:



So overall I would consider the Pentax Ltd. 20-40 as well.

[bandarbalu]

Thanks for the quick advice. Can anyone compare the 17-70 options (or the 16-50) optically to the 18-135? It sounds like the 18-135 has quick and reliable AF, but does it have any problem spots (low light or at the tele end)? I'm not trying to find fault with it, I just want to know what to expect. The 20-40 also fits the bill, although I've found a pretty high percentage of my work ends up in the 35-50mm range on 4/3, so I'm probably better off making sure I cover those lengths (45-70?) with the first lens I get.

G'day, Andrew! I was down in your neighborhood back in '09!

[Merts]

The 18-135 is surprisingly sharp in the middle even when wide open pretty much right though the zoom range and I reckon the edges are reasonably sharp except maybe wide open at 135mm. Stopped down to around f8 it's pretty sharp across the frame at all focal lengths. It's better than I expected it to be. Focus is quick and accurate, and it focuses reasonably close. I reckon it's a really good walk around lens and good value for the money.

[Paul the Sunman]

The 18-135 is surprisingly sharp in the middle even when wide open pretty much right though the zoom range and I reckon the edges are reasonably sharp except maybe wide open at 135mm. Stopped down to around f8 it's pretty sharp across the frame at all focal lengths. It's better than I expected it to be. Focus is quick and accurate, and it focuses reasonably close. I reckon it's a really good walk around lens and good value for the money.

This is my experience too. I would also mention its excellent colour rendition. On the other hand, at the long end, there is noticeable CA near the edges, though this is easy enough to fix in post processing.

[NeilGratton]

I'm extremely happy with my Sigma 17-70mm f/2.8-4.0. I also had one previously on Canon, and it seems just as good so far in Pentax mount. I've only just switched to Pentax, but here are some shots I took with the Canon version: https://www.flickr.com/photos/neilgratton/sets/72157649696640256/

The 70mm end is flattering enough for portraits, and the lens focuses extremely close, so it's very good for close-up work if you don't want to invest in a 1:1 macro. It is a little soft wide-open at 17mm, though.

Of course, it's not weather-sealed, if that's an issue for you. (I also got the 18-55mm WR kit lens, for those occasions when I need the WR).

[starjedi]

This is my experience too. I would also mention its excellent colour rendition. On the other hand, at the long end, there is noticeable CA near the edges, though this is easy enough to fix in post processing.

In the 18-70 range, it behaves like primes at center and not bad at all at edges!

[IchabodCrane]

Thanks for the quick advice. Can anyone compare the 17-70 options (or the 16-50) optically to the 18-135? It sounds like the 18-135 has quick and reliable AF, but does it have any problem spots (low light or at the tele end)? I'm not trying to find fault with it, I just want to know what to expect. The 20-40 also fits the bill, although I've found a pretty high percentage of my work ends up in the 35-50mm range on 4/3, so I'm probably better off making sure I cover those lengths (45-70?) with the first lens I get.

G'day, Andrew! I was down in your neighborhood back in '09!

I have the DA 18-135 and DA 17-70. The DA 17-70 is a bigger lens and is a little heavier, too. The optical quality is a little better but that's because the 18-135 is pretty good already. You'll see the greatest difference at the wide end which might make the DA 17-70 better as a landscape lens. What you might not pick up in some reviews is the DA 17-70 has a little lower barrel distortion at the wide end. If you're one to correct for those things, you'll find the post-corrected comparison increases the effective focal length difference between those two lenses. What's on paper as a 1 mm difference turns out to be more like 1.5 or 2 mm.

I also tried the Sigma 17-70 C and had to send it back. It was very poor (soft) at the wide end, notably worse than the 18-135. Keep in mind mine was a refurb direct from Sigma so maybe that's a factor... I don't know. However, Lenstip also noticed sub-par performance at the wide end in its test of this lens and they called into question why Sigma would go through the long process of completely redesigning the lens from the previous versions if this was the result. They also complimented its extremely good performance at the long end (which I confirmed with the one I tried).

[bdery]

the first lens to make me have second thoughts was the Sigma 17-70 macro when I read the review here and saw the price. No WR seems to be the drawback

If WR had not been that high on your list, that's what I would have recommended. I'n fact, it's still what I'd recommend. Here are the options I'm thinking about:

a)18-135. Has everything but IQ is good, not fantastic
b)16-85. An unknown quantity since it only started shipping. Also, it's expensive for the moment, price will go down soon
c)Sigma 17-70 AND Pentax 18-55 WR. This is what I have. I use the WR when the situation warrants it, the erst of the time the Sigma is my go-to lens. It works very well for me.

[UncleVanya]

I love my 18-135. But I have not directly compared it with most of the other options. My dad recently had the current Sigma 28-70 HSM lens and found it too heavy and bulky. Bear in mind the weight of the faster zoom lenses may make the camera unwieldy for your youngest photographer.

[powasky]

I recently switched from a m43 system (Panasonic G3 that I've used almost exclusively with Panasonic 20mm/1.7) to a K5IIs myself. I was debating between getting a Sigma 18-35 and the new Pentax Ltd. 20-40 and decided to pick up the Pentax and return it for Sigma if it turns out not as sharp as I would hope (note here: I mostly shoot landscapes so I was looking to use the lens mostly around f/8). I recently took the Pentax lens for a spin and I'm very happy with the results:

So overall I would consider the Pentax Ltd. 20-40 as well.

To me, the Sigma 18-35 vs the Pentax 20-40 is not even a debate - Sigma all the way. Unless you really need the WR that is...

[IchabodCrane]

To me, the Sigma 18-35 vs the Pentax 20-40 is not even a debate - Sigma all the way. Unless you really need the WR that is...

Or if you want a lens that weighs about 65% less and is about 40% shorter than the Sigma 18-35.