[Kozlok]

It seems you have two questions, an upgrade to your 18-55, and a different question about a prime lens, unless I don't understand your question properly.

For upgrading the 18-55, there are several choices, it's up to you. The 18-135 is an upgrade, for sure. Especially in the 18-55 range, it's pretty nice. There are several used in the marketplace for very reasonable prices. But if you want even better, the 16-85 is even better. The biggest improvement over the 18-135 will be overall sharpness, but especially at the edges and corners. More important in landscape than portrait.

However, if your budget was very tight, and you did not need WR, I would choose the Sigma 17-70 DC. The first, screw-driven version. I quite like mine; and still use it frequently even though I own the 16-85. Given your stated need for "product photos" the 17-70 Sigma has an extremely useful, near-macro mode. The photos are also quite sharp. Used, they are very inexpensive (~120 USD). They are not WR, so that's the main benefit of the 16-85. Also the 16-85 has a proper silent motor. But anyway, if you want to try the Sigma, I suggest it highly. Get this one: Sigma 17-70mm F2.8-4.5 DC Macro Lens Reviews - Sigma Lenses - Pentax Lens Review Database

[NikoGkotsis]

It seems you have two questions, an upgrade to your 18-55, and a different question about a prime lens, unless I don't understand your question properly.

For upgrading the 18-55, there are several choices, it's up to you. The 18-135 is an upgrade, for sure. Especially in the 18-55 range, it's pretty nice. There are several used in the marketplace for very reasonable prices. But if you want even better, the 16-85 is even better. The biggest improvement over the 18-135 will be overall sharpness, but especially at the edges and corners. More important in landscape than portrait.

However, if your budget was very tight, and you did not need WR, I would choose the Sigma 17-70 DC. The first, screw-driven version. I quite like mine; and still use it frequently even though I own the 16-85. Given your stated need for "product photos" the 17-70 Sigma has an extremely useful, near-macro mode. The photos are also quite sharp. Used, they are very inexpensive (~120 USD). They are not WR, so that's the main benefit of the 16-85. Also the 16-85 has a proper silent motor. But anyway, if you want to try the Sigma, I suggest it highly. Get this one: Sigma 17-70mm F2.8-4.5 DC Macro Lens Reviews - Sigma Lenses - Pentax Lens Review Database

I will definitely look into the sigma one too since i had their 70-300 for 10 years and never disappointed me!
But I think my final choice will be my original thought of getting the 16-85 since the majority of you guys agree and also because of the additional spec research..i think its ideal for my work for now... i can worry about a “super” prime for later since i have been eyeing the 20-40 for a long time but that can wait hahah

[mikesbike]

Your choices are the 16-85 or the 18-135. Both have fans and both have pluses and minuses. I prefer the 16-85, my wife likes the 18-135. Some days my shots are better, some days hers are.

Welcome to the forum. Indeed, for an all-around, multi-use zoom lens, I agree with jatrax. These lenses both bring another factor your current lenses do not offer- the WR (Weather Resistant) build quality. It is not an easy choice to make. Each of these lenses has a thread in the lens section of the forum with a title such as "DA 18-135mm WR show us what it can do" so you can see examples as far as image quality that can be had. It is best to go to the last page (most recent) and go backwards.

Reasons the DA 18-135mm is a good possible alternative include- greater telephoto zoom range, exceptionally fast, accurate autofocus, an amazingly compact design for its zoom range to match well with the KP's compact design, and is capable of very good closeup shots even at the longer zoom settings with very smooth background rendering (bokeh).

Then, as to the DA 16-85mm lens, especially in the zoom range over 50mm- to 85mm, the image quality at or near the edges of the frame, in other words edge-to-edge image quality will be more uniformly of higher quality- closer to that of the central area, which is unusual for such a zoom lens. The edge performance at a setting from 18mm through 50 or 60mm will be closer between the lenses, especially between f/5.6-f/11. Beyond f/11 some quality will be lost by both. This may or may not be of importance for some of your product imaging. If your products will occupy mostly the central area of the photo, the DA 18-135mm quality is excellent practically throughout its zoom range. But if you intend for the product to fill nearly the entire frame, and that even its edges should be sharp, then the DA 16-85mm will more likely be better in that case if over 60mm to 85mm.

As to portraits, your DA 50mm f/1.8 as well as your 50mm f/1.4 are very capable of producing splendid results. The 50mm focal length on APS-C bodies is an ideal one for portraits, as are the larger available apertures.

If you are shooting JPEG images right out of the camera, your new KP's in-camera processor is especially good at doing this, producing exceptionally fine results. Just be sure to set up "Fine Sharpening" in the Custom Image menus by using your thumb dial.

[NikoGkotsis]

Wow thank you so much for that analysis!!!

[mikesbike]

The 50mm focal length on APS-C bodies is an ideal one for portraits, as are the larger available apertures.

In case you are not familiar with how this goes, the larger apertures are the smaller numbers. By letting in more light, they can allow higher shutter speeds, and will reduce depth-of-field (DOF), which is how much of your picture will show sharp focus. A shallow DOF is not usually good for product shots or for landscape photos, but can be good for portraits, where you might want to blur the background to some degree to make your subject stand out better from it. The farther away the background, or for closeups, the less wide the aperture will need to be for this effect. Using a longer focal length lens will also contribute to a reduced DOF. Controlling DOF can be of value for certain product shots as well, depending on the circumstances.

[normhead]

I sold my 18-55 with my K20D a few yers ago to pay for some long glass, but I have many great images taken with it. The 16-85 is the current recommended standard, the 55-300 should replace your Sigma 70-300 as soon as possible. If you're like me, you'll be replacing your Sigma 70-300 images with better images from the 55-300 PLM. I love my 18-135, but I currently recommend (am thinking's of buying for my wife) a DA 16-85. The DA 16-85 was designed for 24 MP sensors like your K-P. The 18-135 was designed for 14-16 MP cameras. Mine works, and I wouldn't sell my 18-135 to get a 16-85, but if I were buying today it would be 16-85. Since I own a 55-300, the 16-55 would actually give me more range, and more range was always why I preferred the 18-135.

The various 17-70s are also good, as well as the 16-50 type lenses, but again, they were designed for less dense sensors. You see that particularly on the edges, where the 16-85 is better.

I own many FF lenses, but the only one I'd recommend for APS-c would be the DFA 100 macro. It's one FF lens that is awesome and not a lot of weight or size. Of course the FA ltd.s would be in the same boat. ASP-c lenses tend to be lighter and therefore more desirable for portability.

My advice is always cover with zooms, in this case the 16-85 and 55-300 PLM, and then after a year analyze the focal lengths at which you shoot before you start acquiring primes. (Of course with your 18-55 and 70-300 you should have pretty good idea.) You DA 50 1.8 will give you excellent low light coverage for starts, and the 35 2.4 is also cheap. I don't like the 35, but hey, if you need a little wider. My first choice here was the 21 ltd. But I already owned a 50 1.7.

They say that HD is <1% more clarity than SMC, however, photography tends to go in doubles and halves, not numbers like <1%. I would have to read the spec sheet to know which is which, just from the lenses I own and I doubt you can tell the difference. But I don't have the same lens in both versions, so I can't provide examples.

[northcoastgreg]

HD is a coating. It eliminates flare in bright sunlight. It does not add clarity to the lens in any other situation. Most Pentax DA primes are quite sharp, whether the old SMC version or the newer HD versions. Sharpness is the same between the two coatings, except in bright sunlight, flare is better with HD.

While this is technically true, there is one sense in which you could say the HD coatings add "clarity," and that is they can add contrast and saturation to an image, and that can provide an illusion of increased clarity. The HD coatings allow more light from the center of the color spectrum to reach the sensor, and that can increase the saturation of warmer colors like reds and browns. These coatings will have more impact in zoom lenses featuring lots of glass, like the DA 16-85. They'll have less impact in lenses with less glass, like the DA Limiteds.

[mikesbike]

The 18-135 was designed for 14-16 MP cameras.

Many very fine lenses were designed around this time and even a long time before, but the DA 18-135mm was not specifically designed to match 14-16mp sensors, that or less is what was available. The lenses were designed to be the best possible for the design goals of lens size, focal length, and lens type. As to being inadequate to match well with higher resolution camera designs since, I found that not to be the case. I was using the DA !8-135mm with my 12 mp K-r as well as my 14.6 K20D even before I got a K-5. I noticed the superior image quality of the K-5, and did so when using this lens as well as with the excellence of the DA Limited prime lenses which were designed before the DA 18-135mm. Then again I noticed improved image quality when I got my KP- again even when using my DA 18-135mm as well as my Limited lenses designed long before. These lenses were not a limiting factor for the camera to demonstrate improvement.

---------- Post added 10-13-20 at 06:01 PM ----------

particularly on the edges, where the 16-85 is better.

This is what has been shown as true, particularly if compared between 60-85mm. However, though for some purposes this can be meaningful to some, the more usual occurrence as the lens is zoomed into a more tele range, the edges become less important, while the central area becomes were the subject of interest lies. In independent tests, the DA 18-135mm proved to have better resolution readings overall at various focal lengths- in the central area, and comparable at the edges even to the DA 16-85mm from 18-through 50mm, especially when at f/5.6 and onward. Then, as zooming farther into tele, while the DA 16-85mm came out easily better at the edges, the DA 18-135mm hangs onto its central area resolution at 85mm (and beyond) far better than does the DA 16-85mm!

So the DA 18-135mm's central area is sharper, even going into the tele range where usually the edges become much less of an issue. The test reviewers should recognize this fact, but often they give too much credence to edge performance at tele settings, or resolution even in corners being (to me) overemphasized in their rating of the lens. Perhaps important for some special need or other, but in general a non-issue.

The DA 16-85mm is a fine lens- I am not in any way saying it is not. But like anything it has its strengths- mainly from what I've seen being its 16mm wider angle, and its edge performance- particularly beyond 50mm to its 85mm maximum. It is also a costlier, larger, and bulkier lens than the DA 18-135mm, and my impression has been the AF of the DA 18-135mm is faster, being among the best of Pentax lenses.

[normhead]

The DA 16-85mm is a fine lens- I am not in any way saying it is not. But like anything it has its strengths- mainly from what I've seen being its 16mm wider angle, and its edge performance- particularly beyond 50mm to its 85mm maximum. It is also a costlier, larger, and bulkier lens than the DA 18-135mm, and my impression has been the AF of the DA 18-135mm is faster, being among the best of Pentax lenses.

Looking at the big picture an 18-135 plus a 55-300 gives you 18-300.
Looking at the big picture a 16-85 plus a 55-300 gives you 16-300.

Mine is a purely practical FL decision.
The 18-135 is a great lens.... but more relevant to those shooters (and there's a lot of them) who never shoot beyond 135mm in any case. Taking one lens, the 18-135 would be my choice. The OP is talking about a 55-300PLM and a 50 1.8 to go wth his lens.

I guess the main point is if he can't afford the 16-85 then an 18-135 will do. With the current emphasis on edge sharpness and CA control, I doubt a lens like the 18-135 would be released today, even though 10 years ago it was one of the best reasons for buying a Pentax. In my mind, a spectacular lens from a different era. There's noting wrong with it that isn't wrong about most lenses from that era. And it fits right into the FA ltd. oldie but goodie mold. It's DC motor is still top notch, and my biggest complaint with the K-1 is there's not an 18-135 equivalent lens for it that measures up.

There has never been a lens made in the last 20 years that doesn't improve it's IQ with each new denser sensor. That doesn't mean their aren't benefits to be had in newer designs.

[NikoGkotsis]

ok folks I know I am taking the discussion to a different direction BUT
what if instead of the 16-85 I go to the 20-40 limited?
I know the range is different but I would be willing to sacrifice it for extra sharpness.

Thoughts?

[jatrax]

Thoughts?

You give up a lot. And I don't think I have seen anything that shows the 20-40 is significantly 'sharper' than the 16-85 in real world images. The 20-40 is a really cool lens, but its not what I would pick for my standard working lens. Others will differ of course.

[NikoGkotsis]

You give up a lot. And I don't think I have seen anything that shows the 20-40 is significantly 'sharper' than the 16-85 in real world images. The 20-40 is a really cool lens, but its not what I would pick for my standard working lens. Others will differ of course.

yea since I posted this I did further research and even though its marvelous lens I do not thing would work for my fast pace and multi-subject commercial daily shooting...

[BigMackCam]

ok folks I know I am taking the discussion to a different direction BUT
what if instead of the 16-85 I go to the 20-40 limited?
I know the range is different but I would be willing to sacrifice it for extra sharpness.

It's far from my favourite DA Limited, but it's surprisingly versatile within its limited focal length range (especially with the reasonably fast variable max aperture), and focuses quite closely for not-quite-macro work. Many folks adore it - I've been on the fence about it for some time, and would much rather shoot with the DA Limited primes.

I think you'd be better served by the DA16-85 or something else with a wide focal length range...

[Des]

what if instead of the 16-85 I go to the 20-40 limited?I know the range is different but I would be willing to sacrifice it for extra sharpness.

I don't have the 16-85, but I've seen a lot of impressive images from it. I do have the 18-135 and 20-40. The 20-40 is quite sharp, but I doubt that its resolution exceeds that of the 16-85. The charm of the images from the 20-40 is more in the overall look, which is similar to that of the other DA Limiteds.

yea since I posted this I did further research and even though its marvelous lens I do not thing would work for my fast pace and multi-subject commercial daily shooting...

I assume you mean you value a wider range of focal lengths for your needs. That makes sense. In every other respect the 20-40 would be just as "fast paced" as the other DC autofocus lenses and would offer a little wider aperture (at the wide end) than the 18-135 or 16-85 (which are have about the same maximum aperture).

If you value sharpness above all else, at a wide range of apertures, you should be looking at macro lenses like the DA 35mm f2.8 Limited macro, FA or DFA 50mm f2.8 macro and Tamron 90 f2.8 or Pentax DFA 100mm f2.8. I have the FA 50 and DFA 100 macros and they are the sharpness kings.

[mikesbike]

yea since I posted this I did further research and even though its marvelous lens I do not thing would work for my fast pace and multi-subject commercial daily shooting...

I have found this lens in the real world to be capable of delivering exceptional image quality for a zoom lens. There really should be a "show what it can do" thread for it. The other two lenses considered here are also very capable within that same zoom range. If your product shoot does not require any more wide angle or any more telephoto reach, then it could do quite well, though not as versatile. However, its main points are extreme portability, combined with its f/2.8 aperture capability at its short end, along with its very compact size- practically ideally designed for the KP. I use mine often for these qualities. I even combine it sometimes with my excellent DA* 50-135mm f/2.8 lens, a wonderful duo with very high-quality along with easy carrying. Excellent quality of construction throughout.

I also use my DA 18-135mm DC WR as an alternate when I will not be needing the faster f/2.8 aperture, and want more versatility yet with high quality. This is the one next in line for a high quality zoom lens having a compact profile that matches well with the KP, along with an exceptionally fast and sure AF. Its wide zoom range being amazing for its compact size, it thus necessitates less changing lenses when I will sometimes additionally take along my DA HD 55-300mm WR lens if I think I might need some extra-long reach. A very practical, versatile, and functional fine-performing package in a low-size form.

The DA 16-85mm HD WR would indeed provide more wide angle, 16mm instead of 18mm or 20mm, but it is also more bulky and more costly.