[royd63uk]

the 18-135 is a super lens and is the one on my camera most of the time

[Des]

A used 18-135 is one third the price of a 16-85 – so there is a significant premium to pay.

Many people get the 18-135 bundled with a camera; when you get it that way it's really cheap. Those bargains tend to flow through to the secondhand market. I've never seen the 16-85 bundled with a camera (a pity because it would be an appealing deal with a higher-end body like the KP). The 16-85 has dropped to around $US450 in the Black Friday sales, but the regular price seems to be significantly higher. And there aren't many 16-85 lenses on the secondhand market. That's probably because there are far fewer sold in the first place and because people who buy the 16-85 tend to do so as a deliberate upgrade, so they are more likely to keep it.

The current best price seems to be about $500 for a new 16-85 against $300 for the 18-135: US Pentax Deal Roundup - Week of December 31, 2018 - PentaxForums.com That's a narrower gap than your original post suggests, but it's still $200 you could put towards your next lens or flash or PP software. (Or you could waste it on food, or rent. ;-)). Maybe more if you got the 18-135 second-hand. With the difference you could get a nice macro lens like the Tamron 90, or a fine portrait lens like the DA 70 (second hand), or a screw-driven DA 55-300 WR, or be well on the way to a good wide angle lens like the Sigma 10-20, Pentax DA 12-24 or Pentax DA 15 Ltd. Or you could get a very capable flash and triggers and modifiers and/or some top quality PP software, or a decent tripod/head. Or you could take a photography course. Any of which might provide better photographic outcomes for someone starting out than any difference in image quality between the 16-85 and 18-135.

Edit: There is a 16-85 for sale in the PF marketplace at present, asking $US400: https://www.pentaxforums.com/forums/24-photographic-equipment-sale/379940-sa...wer-price.html
The 18-135 comes up quite often for around $200, sometimes less. So the gap of roughly $200 seems to hold in the used market as well as new.

[Gbhati01]

Thanks a lot guys, super helpful comments

I decided to go for the 18-135. I also happened to get my hand on one to take some trial shots. I am no expert, but there is a difference in image quality compared to my primes - which is not a surprise.

But I need a workhorse lens which has a decent focal length range. Purely for practical reasons I can’t always shoot with a prime. Weight and size of lens is a big criteria for me, 18-135 is quite a bit lighter and smaller - a perfect travel lens. Price is also a factor, I got a ‘like new’ 18-135 on amazon for $169. The biggest complaint seems to be softness around corners, which I don’t mind as lot of my shots are portraits. For landscape maybe I will invest in a ultra wide prime - but that decision is at least 6-9 months out. As a beginner, I think I have enough lenses in my kit.

Pictures from Des also helped me make up my mind - wonderful shots. A stupid question - are those shots postprocessed or straight out of camera. How do we evaluate when someone uploads sample shots on this forum, if they are post processed then it could be that lens is crappy but editing skills of the photographer are awesome.

One final question - what is a good working range (FL and apperature) of 18-135. Some of you did comment on the FL range, but I am wondering if there is a sweet spot for apperature also.

[aslyfox]

Thanks a lot guys, super helpful comments . . .One final question - what is a good working range (FL and apperature) of 18-135. Some of you did comment on the FL range, but I am wondering if there is a sweet spot for apperature also.

have you reviewed this material yet:

In Depth Review

Pentax-DA 18-135mm F3.5-5.6 Review - Introduction | PentaxForums.com Reviews

here is a link to user reviews of the lens:

SMC Pentax-DA 18-135mm F3.5-5.6 ED AL [IF] DC WR Reviews - DA Zoom Lenses - Pentax Lens Reviews & Lens Database

[mikesbike]

Thanks a lot guys, super helpful comments

I decided to go for the 18-135. I also happened to get my hand on one to take some trial shots. I am no expert, but there is a difference in image quality compared to my primes - which is not a surprise.

But I need a workhorse lens which has a decent focal length range. Purely for practical reasons I can’t always shoot with a prime. Weight and size of lens is a big criteria for me, 18-135 is quite a bit lighter and smaller - a perfect travel lens. Price is also a factor, I got a ‘like new’ 18-135 on amazon for $169. The biggest complaint seems to be softness around corners, which I don’t mind as lot of my shots are portraits. For landscape maybe I will invest in a ultra wide prime - but that decision is at least 6-9 months out. As a beginner, I think I have enough lenses in my kit.

Pictures from Des also helped me make up my mind - wonderful shots. A stupid question - are those shots postprocessed or straight out of camera. How do we evaluate when someone uploads sample shots on this forum, if they are post processed then it could be that lens is crappy but editing skills of the photographer are awesome.

One final question - what is a good working range (FL and apperature) of 18-135. Some of you did comment on the FL range, but I am wondering if there is a sweet spot for apperature also.

For landscape with the DA 18-135mm don't shoot longer than 35mm, and best not wide open aperture. Between f/5.6-9.5 would be at its best. Best focal length would be at 24mm- still a good one for landscape, since it will have minimal front-to-back perspective distortion, yet still wide angle. Edges will be quite fine! For wider angle consider adding the excellent DA 12-24mm f/4.

If your kit lens is the 18-50mm RE DC WR keep it anyway! It is a quite good and remarkably compact zoom lens. I regularly shoot with the KP, but I still use my K-S-2 also, and especially value it with the little 18-50mm. The KS-2 is remarkably small and light for a full-fledged dual-dial WR 20mp DSLR, and with this very compact lens I can fit the ensemble into a large jacket pocket! With a zoom lens yet! Such an idea does not exist with any other brand of DSLR I know of! Hey, mirrorless??

[c.a.m]

One final question - what is a good working range (FL and apperature) of 18-135.

The following work by our very own @BigMackCam should be of interest: Pentax lenses - Resolution performance at various apertures - PentaxForums.com

Scroll down to find the DA 18-135.

I made the following chart based on a test done on a single lens sample by Imaging Resource. I picked off the 'blur index value' from each cell in each of their sharpness/resolution plots, and summarized the results. The percentages indicate the extent of the image that has a blur value of less than 2 units, which is deemed to produce acceptably sharp images. For example, using the 18-135 at 24mm f/5.6 will result in most of the image being sharp. On the other hand, be wary of, say, 68mm f/4.5!

The Imaging Resource review is here: https://www.imaging-resource.com/lenses/pentax/18-135mm-f3.5-5.6-ed-al-if-dc-smc-da-wr/review/


- Craig

[UncleVanya]

The following work by our very own @BigMackCam should be of interest: Pentax lenses - Resolution performance at various apertures - PentaxForums.com

The f/11+ results seem odd. I would expect diffraction to start to bite into the sharpness particularly at f/16.

---------- Post added 01-04-19 at 02:44 PM ----------

I decided to go for the 18-135. I also happened to get my hand on one to take some trial shots. I am no expert, but there is a difference in image quality compared to my primes - which is not a surprise.

Congrats, I'm sure you will enjoy it. Great price!

Pictures from Des also helped me make up my mind - wonderful shots. A stupid question - are those shots postprocessed or straight out of camera. How do we evaluate when someone uploads sample shots on this forum, if they are post processed then it could be that lens is crappy but editing skills of the photographer are awesome.

Some post processing software leaves data in the EXIF or strips EXIF which might clue you in. Otherwise you rely on the person posting to tell you. But even then the silk purse from a sow's ear old saying comes to mind. Your PP skills help but generally garbage in = garbage out.

Technically you have to define post processing. In this case these were shot with my 18-135 @78mm f6.3 on a K-3. The first is the Straight Out of Camera JPG with zero changes. The second is also Straight out of the camera - but was developed IN the camera using the RAW processor inside the K-3. I took the original RAW and applied the Monochrome Bold effect to it. I think the crop came from outside the camera later but I don't recall. I also attempted a version of this using DXO and while the facial features and hair were great the background was still striped and didn't fade out as well as it did here in my first pass so I stayed with the camera's result.





I own many many lenses that are "better" than the 18-135. But carrying the other lenses wasn't in the cards and the opportunity struck - interesting face, engaging personality, and I simply asked and got permission to take his photo. The lens with you is always better than the one you don't have access to!

---

Last edited by UncleVanya; 01-04-2019 at 12:44 PM.

[c.a.m]

The f/11+ results seem odd. I would expect diffraction to start to bite into the sharpness particularly at f/16.

In the chart provided by @BigMackCam for the 18-135, I didn't see data for apertures smaller than f/11. He indicates "no data." Did I miss something?

My summary chart reflects the test by Imaging Resource. I followed IR's convention of 'acceptably sharp' for blur units < 2. Certainly, the sharpness drops with increasingly narrow apertures beyond, say, f/11. For the mid focal lengths, where I show "100" percent, these values would be lower if the blur threshold was lowered.

There will not be total agreement between my chart and the ones developed by @BigMackCam. He drew on a wider set of information, while I used only the IR data.

The graph provided at the IR site gives more details. Click on the resolution graph -- the chart uses sliders to vary focal length and aperture.

In any case, I think this information would be sufficient for @Gbhati01 's needs at this point.


- Craig

[BigMackCam]

The f/11+ results seem odd. I would expect diffraction to start to bite into the sharpness particularly at f/16.

Three possible reasons I can think of, here:

(1) errors in my source data, which came from multiple review sites wherever possible, but sometimes only one if that's all that was available
(2) the cameras used by those review sites being older, lower-resolution models (e.g. K10D) such that the first signs of optical diffraction wouldn't be visible due to relatively low pixel density of the sensor
(3) performance at f/11 with diffraction, is genuinely better than, say, f/8 without diffraction... quite possible, since it's not unusual for consumer grade, wide range zooms to show their best performance beyond f/8

[UncleVanya]

Three possible reasons I can think of, here:

(1) errors in my source data, which came from multiple review sites wherever possible, but sometimes only one if that's all that was available
(2) the cameras used by those review sites being older, lower-resolution models (e.g. K10D) such that the first signs of optical diffraction wouldn't be visible due to relatively low pixel density of the sensor
(3) performance at f/11 with diffraction, is genuinely better than, say, f/8 without diffraction... quite possible, since it's not unusual for consumer grade, wide range zooms to show their best performance beyond f/8

Good points. And my comments were for that embedded graphic not your linked work.

[Des]

Thanks a lot guys, super helpful comments

Ask a good question, as you did, and you get lots of good answers. I'm always struck by the awesome body of photography skill and knowledge here and how helpful and generous people generally are.

I decided to go for the 18-135. ... I need a workhorse lens which has a decent focal length range. Purely for practical reasons I can’t always shoot with a prime. Weight and size of lens is a big criteria for me, 18-135 is quite a bit lighter and smaller - a perfect travel lens. Price is also a factor, I got a ‘like new’ 18-135 on amazon for $169.

Congratulations. That sounds like a very good deal. There was no wrong answer to the question, but the 18-135 is indeed a perfect travel lens. It ticks all your boxes.

I also happened to get my hand on one to take some trial shots. I am no expert, but there is a difference in image quality compared to my primes - which is not a surprise. But I need a workhorse lens which has a decent focal length range. Purely for practical reasons I can’t always shoot with a prime. ... The biggest complaint seems to be softness around corners, which I don’t mind as lot of my shots are portraits.

I've also got the DA 35 f2.4 and I used to have the DA 50 f1.8 as well (I assume that's the 50 you have). They are known as the "plastic fantastics" because each has very high levels of resolution - comparable with lenses that cost 5 times more. They do have more resolution across the frame than the zoom. But @Kypfer made a good point earlier: if you test them and the zoom stopped down to say f6.3 or f8 at 35mm and 50mm, you might be surprised how much resolution the zoom has, particularly in the centre but even at the edges at those focal lengths. Particularly at around 24mm-35mm the resolution of the zoom is very high indeed.

The work from Craig and Mike posted above tends to support that - although don't treat these as gospel, they are just indications, for the reasons Mike has described. I'm going on real world impressions with my copy of the lens - YMMV.

I've got a number of high quality primes and they certainly can give you more "wow" images than a walkaround zoom. When I first got some premium lenses, I was amazed by what they could produce. (The FA 77 Ltd ... WOW! Pixie dust!) But for all that, many of my favourite images have been taken with wide-ranging zooms - the 18-135 or two versions of the 55-300. If I find myself thinking, "I wish I'd had the 35/43/50 macro/77/100/300 for that shot", I try to think, "If I hadn't had the zoom I wouldn't have got the shot and it's really quite good". Uncle Vanya put it well:

I own many many lenses that are "better" than the 18-135. But carrying the other lenses wasn't in the cards and the opportunity struck - interesting face, engaging personality, and I simply asked and got permission to take his photo. The lens with you is always better than the one you don't have access to!

The truth is that most people looking at our images aren't as obsessive about details as we are. They couldn't care less which lens you use. They don't notice the flare spots or the few pixels of purple and green bokeh fringing that we can't take our eyes off. If they are used to seeing smartphone images, any DSLR image is going to look like it has a lot of resolution. No doubt better gear helps you get the most from your skills. But it's developing your skills that really makes your photography better.

For landscape maybe I will invest in a ultra wide prime - but that decision is at least 6-9 months out. As a beginner, I think I have enough lenses in my kit.

Good idea IMO. Don't necessarily leap to a prime though - there are some very good zooms which you should look at too. While I love primes, and the DA 15 Ltd controls a lot of minds (The 15mm Limited controls my mind - club - PentaxForums.com) personally I find the versatility of a zoom very useful in an ultrawide lens. You can't "zoom with your feet" in a close forest or standing on stones in a river (unless you really want to test the WR ). Read up and pose a question when the time comes.

Pictures from Des also helped me make up my mind - wonderful shots. A stupid question - are those shots postprocessed or straight out of camera. How do we evaluate when someone uploads sample shots on this forum, if they are post processed then it could be that lens is crappy but editing skills of the photographer are awesome.

Glad you found them useful. More on my Flickr page if you are interested: Pentax DA 18-135mm f3.5-5.6 sample images - Des(Australia) - Flickr

There's a whole PF thread of images taken with the 18-135 where you might find some inspiration: DA 18-135 WR, Show us what it can do - PentaxForums.com. It's a good place to post questions about the lens too.

Yes all the samples I posted were shot in RAW and PP'd. I use DxO software (currently DxO PhotoLab 2, Elite edition). I find it really capable and easy to use. If there is a module for your particular camera and lens combination (there is for the 18-135 with every Pentax DSLR from the K10D onwards) it automatically corrects an image for distortion, vignetting, chromatic aberration, etc - that is a great start. Then you can adjust white balance, exposure, and colours, straighten horizons, increase or reduce contrast and microcontrast, reduce haze and do and many other things. It also lets you make adjustments to a particular part of the image: for example, you can select a subject and alter the microcontrast, sharpness, exposure and WB for that subject alone.

Here's a before and after example. (K-30 and DA 18-135, 36mm, 1/45th second, f6.7, ISO 140. I suspect f8 would have been better, even at the price of bumping the ISO a little.)

RAW image converted with no processing. Complete with nasty dust spot in the middle. It's not bad, but kind of meh.


Image after processing.


Using presets and with practice in using the software, it's about 2 minutes' worth of processing. My editing skills are getting better, but they are far from awesome - and they were much more limited when I did this one in 2016. All that happened here was: default corrections for the lens and camera combination, white balance is unchanged, dust spot removed, a little tweaking the exposure levels, increase microcontrast, increased vibrancy, cropped. The biggest change came from increasing the clarity (in DxO it's called ClearView, and it's one the program's best features).

None of these edits is putting in something that isn't there (except sky where the dust spot was); it's just tweaking the output from data that's already there in the RAW file. I would be doing the same with any lens.

Although I use DxO there are many other options too. I haven't tried a lot of other software so I can't really compare.

I have shot in RAW (initially RAW + jpg but now just RAW) since I got a K-30 at the end of 2013. My biggest photographic regret is that I didn't shoot RAW in the previous 6 years since I got my first DSLR in 2007 (after about 24 years with a film SLR). If you aren't already shooting RAW, at least switch to RAW + jpg and save the RAW images. Down the track, when you have the time and inclination, and some experience with PP software, you will at least have them available to play with.

I think you'll find that most people here shoot RAW and post-process their images, or at least the ones they post here. Having said that, in-camera conversion is quite good and getting better, as Uncle Vanya's example shows. But RAW + PP gives you a lot more control and much greater scope to get the best from your images.

One final question - what is a good working range (FL and apperature) of 18-135. Some of you did comment on the FL range, but I am wondering if there is a sweet spot for apperature also.

As the posts by @Mikesbike and @c.a.m. suggest, you'll get more resolution by stopping down (ie narrowing the aperture) one or two stops.

The maximum aperture increments for the 18-135 are:
18mm - f3.5
20mm - f4
28mm - f4.5
70mm - f5.6

So from 70mm-135mm one stop down from the maximum aperture means f8 and two stops means f11. According to the chart that still won't give you a big % of the image area that is sharp, but I can say from experience that it will give you much better resolution in the central area that is sharp. Go for f8, even if you have to bump the ISO up a bit (preferably not more than 1600 with the K-S2), and you generally can't go wrong. (Of course that doesn't mean you just shoot everything at f8, only that that's a sweet spot for resolution.)

As for focal length, for my part I'd choose the focal length that was suitable to create the image I wanted, rather than fit the focal length to the best resolution. So, for example, while the resolution in the corners would be better at 50mm than at 85mm, I wouldn't for that reason shoot at 50mm and crop to get the field of view of 85mm, if that was the field of view I really wanted. If you were going to do that, you might as well just take the 50mm prime. But try the comparison yourself with the 18-135 and your primes and see how it comes out. (Your subject would take up fewer pixels with the wider angle and the perspective would be different.)

[c.a.m]

@Des, that's a great overview and summary! I agree totally with your remarks on sharpness across the various focal lengths and apertures. Nice sample images, too, which underscore the benefit of post-processing RAW files.

As a side note, may I mention the thoughts that I had when researching a new zoom several years ago, before I got the DA 18-135? At first, I was set on the new-ish DA 20-40mm Limited, but it was quite pricey here in Canada, about $1000. The 18-135 was about half the price. After looking at reviews, resolution tests, and real-life images, I settled on the 18-135. I concluded that it would be very good between 20mm and about 60mm, and I've treated it as sort of a wide-to-near-tele zoom with a bonus extension to 135mm when I need the reach.

My heart is still set on the 20-40, though! Must be the Takumar styling cues.

[Gbhati01]

Thanks again everyone for their valuable comments - special shout to Des.

Just received my lens, will be trying it over the weekend. Hoping it’s not a bad copy.

[Des]

Thanks again everyone for their valuable comments - special shout to Des.

Happy to help.

Just received my lens, will be trying it over the weekend. Hoping it’s not a bad copy.

That's exciting!

Don't worry too much about bad copies. But if you want to do the full gamut of tests, here's advice from an expert: Lens Rentals | Blog

Don't be surprised or concerned if the zoom ring or focus ring is a bit stiff to start with. It will loosen up. If the zoom is too loose (zoom creep) there's nothing you can do; just decide whether you can live with it and if not send it back.

Get the AF sorted: Fixing Front and Back Focus - Introduction - In-Depth Articles (Some adjustment is common. It's only an issue if it's beyond the camera's range of fine AF adjustments or if there is a marked difference at different focal lengths because you can only have one adjustment per lens.)

Quick check for decentering: How to Check Your Lens for Decentering - Articles and Tips | PentaxForums.com

Then go and try as many different things as you can. Have fun.

[Paul the Sunman]

Thanks again everyone for their valuable comments - special shout to Des.

Just received my lens, will be trying it over the weekend. Hoping it’s not a bad copy.

I have 14 Pentax lenses. No "bad copies" yet, though the DA 16-85 did lose a screw and need fixing.