Question

Really read this Understanding Boke by Harold M. Merklinger
It's an article on luminous landscape by Harold M. Merklinger 1996, he has writing a lot of books about focusing so I believe he knows what he is writing about.
If you want to read one of his books link

So read the article Understanding Boke and then we will talk further

Gosh....Stefan.
You are making a case out of this, don't you :
Can we at least agree that the term boke(h) in general is referring to the way OOF highlights or distinctive background areas are shown in a picture?

This is a bit like: Asking for the time, and getting answered how a watch works.

Martin.( who fears bokeh can now join the illustrious group of politics, religion or MJ......AKA best avoided.:blush

I can agree partially on that Martin, the term "distinctive background areas" is too undefined

Lets keep it simple and keep it with OOF highlights only.


From left to right - bad - bad - average - good bokeh.

You can not make it simpler as that, it's you that makes it far more complicated and putting far more meaning in the word then it really is

The only thing we have to fear is fear itself.

So, having read the article linked to by Stefan, i wonder if we think there's something in this or whether it's a csae of "The Emperor's New Clothes" or maybe the descriptions at a wine tasting.

What I can say is that if there is such a thing as good bokeh, then my Pentax 55-300mm certainly possesses it as it renders out of focus areas beautifully. But this is not just the highlights as the whole area is soft and lucious.

I'm still thinking it over...

Instead of titling your thread "Question", it would be more helpful to write: "What is bokeh?"?

This will achieve four things:

1 It will not waste the time of people who are not interested in reading about bokeh.

2 It will encourage bokeh experts who are short of time and who might otherwise skip past it, to visit the thread and scatter a few pearls of wisdom in your direction.

3 It will make the search facility more effective. If the definitie guide to bokeh is posted to this thread, it may never be found because people looking for bokeh are unlikely to insert the word "question" into their search.

4 It makes it much easier to scan the forum if people title their topics intelligently.

So, please, take a few micro-seconds to think up a proper title.

G

I think for most subjects the more blurry(fig3, also sometimes called butery, smooth, silky) the OOF areas the better the effect on the image.
However it allways depends on the subject. Sometimes better defined edges in the bokeh work better. Its a matter of the subject and of taste.

What one should do is identify the primary subjects on which one wants to use the lens and determine what type of bokeh one prefers for that subject.

Tipically the objective of using a small depth of field is to lessen the impact of other elements and enhance that of the subject in focus. To that effect, larger apertures with smooth transitions between shapes in the OOF region is desirable.
However on might want a certain character to the opposite region (to the one in focus), we dont want the background to be discernible, but it has a definate role to play, a certain impact is desired. To this effect very smooth transitions might not work, lenses with defined edges might give a nice brush like effect which works better.

Some examples:
Bad bokeh:


I like the brush like effect, but here its too distracting.


Good bokeh


I like the little pale white balls decorating the background.



Because the rest of the plants are soo poorly defined, the bee and flower really stick ou.



A better defined background here works best, and the harder edges help IMO.
Sorry don't have bad examples of smooth bokeh, but here it wouldn't work for example...

What would be more convincing would be two images of the same subject at the same time, one with a lens perceived to have good bokeh and one with a lens perceived to have poor bokeh.

I suspect this may be difficult to deliver convincingly, but I'd be happy if someone can prove me wrong.

I did my best John, here are the photos.
The arrangement was for glasses and a flashgun right of me to make highlights in the glass.
Tried to get the same frame with all of them but didn't wanted to spend to many time perfecting it so forgive me that.
all lenses wide open

image order is:
full frame
first glass
3th glass
4th glass

DA18-55 at 35mm
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2887.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2887-2.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2887-3.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2887-4.jpg[/IMG]

DA40
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2884.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2884-2.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2884-3.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2884-4.jpg[/IMG]

DA*50-135 108mm
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2882.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2882-2.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2882-3.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2882-4.jpg[/IMG]

DFA 100mm
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2883.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2883-2.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2883-3.jpg[/IMG]
[IMG]http://i282.photobucket.com/albums/kk244/Anvh/_IGP2883-4.jpg[/IMG]

Sorry I really need to go so won't comment on the bokeh.
the first glass bokeh always looks pretty good but the 3th glass the all look pretty bad.
4th glass looks like an improvement but still not so good

Thanks for putting in the effort Stefan. It's becoming clearer that we are thinking along totally different lines as this is not really what I had in mind.

This is more how I was thinking:
[IMG]http://i240.photobucket.com/albums/ff250/johnriley1uk/033-Cornflowers.jpg[/IMG]
I think of the way the background is reproduced here can be described as good or bad bokeh and it would be interesting to see the same shot with another lens, but taken at the same time.

Unfortunately I can't provide one, but FWIW this one was the 55-300mm DA zoom.

Does this have good bokeh?

IMHO, yes, it has!

My argument is that we cannot rigidly say that a lens has bad bokeh or good bokeh. There is bokeh that works well and bokeh that does not work for a certain photograph. In that sense, the same lens can produce good and bad shots, bokeh wise.

Now, the majority prefers silky smooth bokeh, hence they will deem the lenses that deliver such a bokeh as better. My point is that one should not make that a rigid stance.

That's fair enough. Always an open mind.

If it looks good, it is good?

Problem. I don't have a non-Pentax lens!

G

John then you probable have the meaning of the term bokeh wrong.

Wiki
Bokeh (derived from Japanese, a noun boke 暈け, meaning "blur" or "haze") is a photographic term referring to the appearance of point of light sources in an out-of-focus area of an image produced by a camera lens using a shallow depth of field.

When you look back at the links that I've posted it only went about that and not the whole background. If you can prove that bokeh isn't about a point of light then I stand fully correct of course.

Edumad had it quite right with his photos.



Is you can see it's the bright ring bokeh and it is highly distracting and not any good, just like he said.




This photo has the average bokeh, the evenly lighted highlights.
It's really less distracting then the first photo because of that and it has a nice and pleasant effect.
Can you imaging the bokeh being the bright ring ones, they would have been distracting here as well.




This one has the good bokeh with the bright core and smooth edges it seems.
You can't find a hard edge really anywhere.




This one has the average bokeh.
with some lines in the background you can see it's build up with with all of those highlight circles (bokeh) you can hardly define the edges between the circles but you can see the edge of the line quite clearly and the lines are evenly filled.

There is no such thing as right or wrong when it comes to the meaning of words. Some photographers use "bokeh" for the appearance of OOF light points, others for everything that is OOF.

"Bokeh" is the Japanese word for fuzzy. It has only recently begun to enter the English language as a photographic term. Clearly, its meaning is still fuzzy!

"Main Entry: bokeh
Part of Speech: n
Definition: a Japanese term for the subjective aesthetic quality of out-of-focus areas of a photographic image
Example: The bokeh, or quality of the blurred image in the photograph, was described and discussed.

Dictionary.com's 21st Century Lexicon"

http://dictionary.reference.com/browse/bokeh