[Des]

What a good question @madison_wi_gal and a typically interesting discussion.

Even the DA 18-135mm DC WR lens is more than decent, and can deliver some quite good closeups, pretty surprising for a super-zoom type of lens

That's true. But the 18-135 can also produce horrible bokeh.

I think we need someone to post (if they can locate) an image having a really nervous, maybe even crazy-nervous bokeh in the background.

Here we go, with the DA 18-135. I believe the term for parallel lines like this is "nisen bokeh".


It seems to be common with cheap zooms. I used to get it with the DA L 55-300 at times too. (Another reason to stop down with this lens.) Note the bokeh fringing too.


The bokeh is more pleasant and reliable with more recent zooms like the DA 16-85 ...


... or DA 55-300 PLM:


Good article about bokeh here: Understanding Bokeh | B&H eXplora

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Last edited by Des; 06-03-2022 at 04:41 PM.

[madison_wi_gal]

What a good question @madison_wi_gal and a typically interesting discussion.

That's true. But the 18-135 can also produce horrible bokeh.

Here we go, with the DA 18-135. I believe the term for parallel lines like this is "nisen bokeh".


It seems to be common with cheap zooms. I used to get it with the DA L 55-300 at times too. (Another reason to stop down with this lens.) Note the bokeh fringing too.


The bokeh is more pleasant and reliable with more recent zooms like the DA 16-85 ...


... or DA 55-300 PLM:


Good article about bokeh here: Understanding Bokeh | B&H eXplora

Dagnabbit I need better lenses? Meh, more LBA on the way I guess.

[GUB]

I think we need someone to post (if they can locate) an image having a really nervous, maybe even crazy-nervous bokeh in the background. Of course, if that is the effect desired, then "bad" bokeh becomes "good" bokeh.

I think this would qualify as "nervous" bokeh. In my opinion it is certainly less than ideal.
In this situation I don't think of it as a fault of the lens - rather a combination of the texture of the background and its distance from the subject.
NZ Whio courtesy of the K-1 and a vintage Nestar 400mm probably stopped down

[madison_wi_gal]

How about this one?

Attached Images

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[GUB]

Not so much nervous - just out right puke inducing!
SMC 400 - 600 mirror on the K-1

[GUB]

But same lens on same camera. An example of how it is often about the environment rather than about the lens.

[Ian Stuart Forsyth]

As others have stated that bokeh is the quality of the blur not the amount, when we have a large amount of blur the quality of the bokeh needed to produce a pleasing OOF area is less. When the amount of blur produces overlapping patterns the quality if of the bokeh the lens produces becomes more important.



Here I have enough separation from the background that the quality of the lens bokeh is less important as there is more separation with the OOF areas









Here the quality of the bokeh the lens produces is more important in creating a more pleasing OOF area as the background is not so heavily blurred with patterns that can cause problems


Next is a lens can produce better or not pleasing bokeh depending on whether the OOF area falls in front of focus plane or behind, some lenses can produce good bokeh front and back.






A real challenge for a lens bokeh is having both objects in front of the focus plane and behind it with repeating patterns near the subject.



Also there is the quality of the bokeh balls, the highlight or small light point sources. Lenses can produce cat eyes, onion ring, color fringe or nice round bokeh

One may what to take an image with less exaggerated OOF areas while maintaining pleasing bokeh in those OOF areas.






Here I was using ƒ 22 but still wanted the OOF area to be pleasing so the lens used is one that has pleasing bokeh

[beholder3]

I think we need someone to post (if they can locate) an image having a really nervous, maybe even crazy-nervous bokeh in the background. Of course, if that is the effect desired, then "bad" bokeh becomes "good" bokeh.

The Leica Noctilux 50mm F1 lens is an example of a poorly overcorrected old lens that produces absolutely disgusting bokeh:
https://images.squarespace-cdn.com/content/v1/5115eb0de4b0cd4cc714ba99/15169...g?format=1500w

Here the CA overcorrection leading to brightly outlined bokeh balls is especially obvious:
https://images.squarespace-cdn.com/content/v1/5115eb0de4b0cd4cc714ba99/15169...G?format=1500w

It is a very good example for this discussion because spec sheet wise noobs could assume a 50mm F1 lens is great for "bokeh". In reality it is absolutely not (unless you have a very special taste of course).

On the great bokeh side I think the DFA* 50 renders things extremely smooth and pleasing:




---------- Post added 4th Jun 2022 at 09:23 ----------

How about this one?

In my humble opinion the bokeh is nice.

But you shouldn't ask us about it. The image has to please you and potentially the people you care about most if they like your images.

Bokeh is a pure matter of personal taste.

[RICHARD L.]

That's true. But the 18-135 can also produce horrible bokeh.

The DA 18-135 mm f/3.5-5.6 ED is not so bad, in reality.

Like I said earlier, check for "visual trash" in your out-of-focus background before you trigger the shutter. You can close your diaphragm just before exposure to visually check the final rendering.

Regards

[GUB]

The Leica Noctilux 50mm F1 lens is an example of a poorly overcorrected old lens that produces absolutely disgusting bokeh:

I think my K50 1.4 has issues. and can compete with your Noctilux. Throws in a dose of ca in the bokeh balls to boot. But it lacks the swirl of your one.

[beholder3]

I think my K50 1.4 has issues. and can compete with your Noctilux. Throws in a dose of ca in the bokeh balls to boot. But it lacks the swirl of your one.

You are right. Many old fifties look like that. To me: cringeworthy.

[Rondec]

People have made a lot of good points already. Bokeh is certainly not the most important thing in a lens -- there are plenty of situations where you will try to have everything in focus and it isn't important. The DA 15 limited is a very nice lens, but doesn't make very nice bokeh.

Macro shot because of their closeness tend to have more narrow depth of field, even when you are stopped down. This is the DFA 100 macro at f8.



The DA 55-300 isn't a wonderful lens, but if you are pretty close to your subject it will smooth out the background.



The harder test is what lenses do with "busy" backgrounds. Some just look a lot smoother than others.

This is the DFA *70-200mm and this is the sort of background that might not look so good with certain lenses:



This is the DFA *85 and it has really nice rendering too.



I have always liked the DA *55, but it tends to get a little busier with its rendering.



Anyway, I think beauty is in the eye of the beholder (not beholder3) and so if you are interested in a new lens (who isn't?) then it is best to look at different images and see what clicks with you. I think out of focus rendering is most important for a lens that you are using for portraiture or macro type shots. If you don't do much of that, then it probably isn't as important. A lens like the DA 15 limited or even a 18-135 is probably not as important to have strong out of focus rendering because you are going to be mostly stopped down when you shoot with it.

[madison_wi_gal]

In my humble opinion the bokeh is nice.

But you shouldn't ask us about it. The image has to please you and potentially the people you care about most if they like your images.

Bokeh is a pure matter of personal taste.

Thanks, I do like it, but I was mostly asking if this was an example of bokeh. I think it is.

[beholder3]

Thanks, I do like it, but I was mostly asking if this was an example of bokeh. I think it is.

Bokeh is an attribute and not "a thing", so any of your images will contain bokeh to some degree and all will kind of be examples.

[mikesbike]

What a good question @madison_wi_gal and a typically interesting discussion.

That's true. But the 18-135 can also produce horrible bokeh.

Here we go, with the DA 18-135. I believe the term for parallel lines like this is "nisen bokeh".


It seems to be common with cheap zooms. I used to get it with the DA L 55-300 at times too. (Another reason to stop down with this lens.) Note the bokeh fringing too.


The bokeh is more pleasant and reliable with more recent zooms like the DA 16-85 ...


... or DA 55-300 PLM:


Good article about bokeh here: Understanding Bokeh | B&H eXplora

Very good examples! How did you get such a good example of horrible bokeh from the DA 18-135mm? A certain FL or aperture or both?

---------- Post added 06-04-22 at 12:41 PM ----------

Thanks, I do like it, but I was mostly asking if this was an example of bokeh. I think it is.

Indeed so.

For LBA with reason behind it, a compact lens well-known for excellent bokeh, and one of my favorite lenses overall, is the HD FA 77mm f/1.8 Limited. It would fit in nicely for a compact combo kit with your DA 15mm, and 20-40mm Limiteds. The HD DA 70mm f/2.4 Ltd works well for this also (I have it too) and can provide superior edge-to-edge performance at wider apertures, but the 77mm offers a more substantial jump in reach, is a stop faster for low light situations, and is even better for bokeh. Though not quite as compact as the HD DA 70mm, it is still very compact, in fact remarkably so considering its FL and aperture. Such compactness would be especially nice on your K-01, but still nice with your K-3 III, and with outstanding image quality. The DA 70mm Ltd years ago was tested out by Pop Photo as actually being 65mm as I recall, while they had tested the FA 77mm Ltd as right on at 77mm. It is common for even high-end lenses to not quite meet their stated FL, but the FA Ltds tested right on, hence their odd stated FLs were put there as a matter of dead-on accuracy, being totally honest and reflecting the precision they represent.