[Outis]

So, I finally got a good (I think) copy of the 20-40mm Limited and it doesn't wow me. It's really mushy wide open and in certain situations the bokeh feels harsh and ugly.

But it seems like everyone loves it. I'm really puzzled. What happened? I'm sad because I really wanted to love this lens.

I think I'm going to send it back because it's just not $350 better than the 18-55.

[MarkJerling]

How about you post some photos?

[a5m]

You may have gotten a bad copy. I understand how you are feeling but I think you should try and have it exchanged and give another copy a try before giving up on it.

Just FYI my copy is not tack sharp at f/2.8 between 20-23mm. I think that's how all of them are. But when you stop down a bit the sharpness increases dramatically.

[clackers]

So, I finally got a good (I think) copy of the 20-40mm Limited and it doesn't wow me. It's really mushy wide open and in certain situations the bokeh feels harsh and ugly.

But it seems like everyone loves it. I'm really puzzled. What happened? I'm sad because I really wanted to love this lens.

I think I'm going to send it back because it's just not $350 better than the 18-55.

But does your copy represent everyone else's, Outis?


Test all your new purchases (including focus by LiveView to check if microadjustments are needed on your body), if you've got a lemon, send it back.

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Last edited by clackers; 04-13-2016 at 07:00 PM.

[Dice]

That's okay send it back. My sense after quite a few threads about this lens is either people get it or don't. There are lots of lenses out there. And I'm sure you will find one that does what you need it to do.

[Outis]

How about you post some photos?

Let's go with this for sharpness issues (though there were some examples that were worse-- this is just the one on the memory card in my computer.) Check out the trees in the upper right hand corner.

For bokeh, there's these. Background blur is busy and ugly:


Specular highlights off the car are like fish eggs:


---------- Post added 04-13-16 at 10:23 PM ----------

You may have gotten a bad copy. I understand how you are feeling but I think you should try and have it exchanged and give another copy a try before giving up on it.

Just FYI my copy is not tack sharp at f/2.8 between 20-23mm. I think that's how all of them are. But when you stop down a bit the sharpness increases dramatically.

Yeah. I'm already on my third copy of the lens. The first two had decentering issues, and at this point I'm just kind of exhausted. I was willing to go through several copies with my 14mm Rokinon because they're known for poor QC, but I feel like from Pentax this is a little ridiculous.

[Dice]

What f stop were the pictures taken? What focal length were they? The first image....most lenses except for very fast lenses would be able to blur all that stuff out. I know my DA21 DA35ltd wide open wouldn't either. With the second image is it possible the upper right is outside of the focal plane. Because you don't link to a full size image and it is dark I can't tell. The areas that are in focus appear to be quite sharp. If you were focusing on the first x-mas light perhaps there is some back focusing as the area farther from the light is also quite in focus.

But again it seems like you are unhappy and frustrated. Send it back. You may have chosen a lens that won't do what you need it do.

[aleonx3]

I am not sure what you are expecting from this lens... or perhaps you may have a bad copy. This is one of my go-to lens mostly for its focal length range which is suitable of street and event photography, plus it's reasonable sharpness even with wide-open aperture at all focal lengths . There are other lenses that can give nicer bokeh (eg. FA 31 or FA77), but I don't think this lens in particular would be my choice if I mostly opt for better bokeh. As for focus accuracy, it is not just lens issue, that will also involve the camera fine adjustment settings. BTW, I also like the image rendering property of this lens (like most of the prime lenses) that give more 3D-look with minimal or no distortion.

K3_P3521-1
K3_P3518-1
K3_P2556

[ScooterMaxi Jim]

I have to at least express some sympathy with Outis regarding rendering. Sure, a lot of zooms exhibit poor rendering, but the 20-40 seems to really bring in out in contrasty situations. Somehow, at only 2:1 you could expect a bit better. On the other hand, in subtler lighting I have seen the 20-40 exhibit lovely depth and no harshness. The lens has strengths, but the weaknesses are hard to overlook.

[a5m]

Let's go with this for sharpness issues (though there were some examples that were worse-- this is just the one on the memory card in my computer.) Check out the trees in the upper right hand corner.

For bokeh, there's these. Background blur is busy and ugly:


Specular highlights off the car are like fish eggs:


---------- Post added 04-13-16 at 10:23 PM ----------



Yeah. I'm already on my third copy of the lens. The first two had decentering issues, and at this point I'm just kind of exhausted. I was willing to go through several copies with my 14mm Rokinon because they're known for poor QC, but I feel like from Pentax this is a little ridiculous.

I reread your original post and realized you had tried more than one copy. Third copy though . Maybe fourth time is the charm?

I know these are amateur shots of christmas lights which admittedly make it easy to get nice bokeh but I think they came out good.

[NZ_Ross]

I own a copy of this lens that I brought off a fellow PF member a while back. I made sure through a number of sample images that I had a sharp copy before I purchased the lens - the seller was happy to cooperate with this. The lens was tested at all FL. I have been very happy with the lens, and it is my go to walk around lens, to the point that I have sold my 18-55mm WR - I just wasn't using it.

The attached image was taken 2 days ago at 40mm, f4 - I have no complaints. Yes, my Zeiss 35/2 would have given me a better image - but it wasn't on the camera at the time, the light was changing very fast, and it is 2 times the cost of the DA 20-40 Limited

The DA 20-40 Limited is a lens that has been noted as having some sample variation - making sure you get a good one seems to be the trick.

[DSims]

Outis, don't feel bad - it's really not a special lens. The fact that it's now discounted almost 50% may be a clue (although lenses like the 100 WR Macro are an exception to this idea). If we could see 5-10 years into the future at the comparative used prices of this lens we'd get a clearer idea of how good it is - I'm thinking around $300 (or maybe less) for this one. But of course you can simply judge with your own eyes right now.


You have 3 great Ltd primes - 15, 31, and 77 - all of which I've owned. This isn't in their league.


Those who have this lens and like it, just ignore me and keep on loving it - no harm done and you can continue to be happy. But I've never seen anything special out of this lens. I'd much rather have my FA20-35/4 back, if I needed such a lens. For that matter, I also prefer my F24-50/4.


No, I haven't owned this lens, but after owning 20 or 30 of the best Pentax lenses (I lost count) and diligently studying others' photos before purchasing them, I gained a pretty good understanding of what a lens would give me - even before it ever arrived. This is not a lens I would purchase.

So don't feel guilty Outis. I don't think you're missing anything here.

[janneman]

For bokeh, there's these. Background blur is busy and ugly:

I am afraid that might be just the background. I do have similar shots with the ground visible and littered with stuf and all my lenses, including the Voigtlander 125/2.5, the 31/1.8, FA*28-70 are, at certain apertures, perfectly capable of producing horrible bokeh results under those conditions

[kh1234567890]

I am not sure what you are expecting from this lens... or perhaps you may have a bad copy. This is one of my go-to lens mostly for its focal length range which is suitable of street and event photography, plus it's reasonable sharpness even with wide-open aperture at all focal lengths .

What is the point of removing EXIF data from the example shots ?

[Outis]

Oh, here you go. You can get all the EXIF data off my photostream.