90mm f2.8 lens bokeh- no such thing as a stupid question...but

charybdis

FoxT wrote: »

I'd feel much better,but would learn less. I post here to learn, I post in the pervy forums to feel good. 2 different things, entirely!

Honestly, One of the main reasons I participate here is to learn. Not necessarily by learning from what others have to say, but learning from having to more closely examine my own understanding of things and having to express it in an intelligible and coherent way.

Thecageyone

You just seem to over complicate the straight forward at times Char

FoxT

And, finally... this was the colt I had in mind...

Promac

Nice bokeh with no circles:

cnocbui

charybdis wrote: »

OK.

I did say "heavily", although I do think their effect is greatly overstated.

Comparing entirely different lenses that happen to have different numbers of blades in their aperture diaphragm then declaring any differences between them are due to the number of blades isn't exactly a rigourous test. Do you think that two lenses of the exact same composition apart from having different amounts of aperture blades would look drastically different?

Drastically no, noticeably yes.

Why did they stop a 9 blades when making the STF 135mm? Many lenses have more than 9 blades, so surely a lens designed explicitly for "superior bokeh" would have more, given that it's such an important factor?

Law of diminishing returns i would imagine. Turn that question around - why not just
three blades?

From a rather dense Zeiss technical paper on bokeh, this comment was made"

In summary we can say that the shape of
the iris can become visible in the picture
either obviously as a decorative feature or
as a disturbing artefact and that it can betray
interesting facts about the lens to us.
However, the iris can remain totally invisible
in many pictures. Yes, and if we use a lens
with the aperture fully open, it can of course
play no role at all.

Nevertheless or perhaps in just such a case
there can be major differences in the bokeh.

http://www.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CLN_35_Bokeh_EN/$File/CLN35_Bokeh_en.pdf

Also, the people commenting on the "superior bokeh" of the lenses with more rounded aperture diaphragms probably also subscribe to the idea that the determinant in what makes "good bokeh" is the shape of out-of-focus points of light.

In my case, I do not principally consider out of focus highlights.

In the other recent thread about the top 6 portrait lenses, I note that two have 8 blades, 2 have nine, two I could find no spec for and the also mentioned sigma has 9.

charybdis

cnocbui wrote: »

Drastically no, noticeably yes.

I would say it is unnoticeable in all but very few circumstances.

cnocbui wrote: »

Law of diminishing returns i would imagine. Turn that question around - why not just
three blades?

I'm not saying there isn't reason to use more aperture blades, but one would think that - assuming the lens was designed for bokeh superiority and that the number of aperture blades is an important factor - they would've designed it with more. There's a Pentacon 135mm f/2.8 lens that has 19 aperture blades, for example. Why would they put so much effort into building a lens for this expressed purpose, only to fall short on the number of blades?

cnocbui wrote: »

From a rather dense Zeiss technical paper on bokeh, this comment was made"

From the exact same paper:

Zeiss wrote:

Sometimes the phenomenon of the individual
iris images is equated with “bokeh’; under this
heading one finds collections of pictures in
which iris images are mixed with photos of
soap bubbles. But this is not what is meant by
“bokeh”. In the iris image the lens is reading
the cards to a certain extent but what
significance has all this for the reproduction of
image areas in which there are no highlight
areas?

In the following examples of photos we will see
that one should not over-estimate the
significance of the shape of the iris

cnocbui wrote: »

In my case, I do not principally consider out of focus highlights.

Fair enough, but you can't speak for the other people's statements you're using to support your argument.

cnocbui wrote: »

In the other recent thread about the top 6 portrait lenses, I note that two have 8 blades, 2 have nine, two I could find no spec for and the also mentioned sigma has 9.

That's probably true, but I don't know what it proves. As I said earlier in the thread, all the lenses designed by Zeiss (the people whose whitepaper you just quoted) for Hasselblad have five-bladed aperture diaphragms.

cnocbui

charybdis wrote: »

That's probably true, but I don't know what it proves. As I said earlier in the thread, all the lenses designed by Zeiss (the people whose whitepaper you just quoted) for Hasselblad have five-bladed aperture diaphragms.

It proves that the lenses I could find the data for all have closer to 9 plades than 5.

The Zeiss 85mm f/1.4 Planar T* was one of the ones with 9 aperture blades. You were saying? :rolleyes:

charybdis

cnocbui wrote: »

It proves that the lenses I could find the data for all have closer to 9 plades than 5.

That is true, but I still don't know what you think it proves.

cnocbui wrote: »

The Zeiss 85mm f/1.4 Planar T* was one of the ones with 9 aperture blades. You were saying? :rolleyes:

I said:

charybdis wrote: »

the lenses designed by Zeiss for Hasselblad have five-bladed aperture diaphragms.

humberklog

Promac wrote: »

Nice bokeh with no circles:

Now I'd have that that's good control of DOF but not Bokeh. Am I way off?

FoxT

I agree - my (improved ) understanding of bokeh is that it is the rendition of out-of-focus highlights, and I don't see any in this pic.

humberklog

FoxT wrote: »

I agree - my (improved ) understanding of bokeh is that it is the rendition of out-of-focus highlights, and I don't see any in this pic.

Careful now, it's a flipping minefield out here.

charybdis

FoxT wrote: »

I agree - my (improved ) understanding of bokeh is that it is the rendition of out-of-focus highlights, and I don't see any in this pic.

I wasn't going to comment, but since you asked (before you edited your post):

humberklog wrote: »

Now I'd have that that's good control of DOF but not Bokeh. Am I way off?

I'm not really sure it evidences good control of depth-of-field. It's certainly shallow depth-of-field, although I don't think there's really much evidence of control other than making it as shallow as possible for that composition.

The bokeh is fairly neutral, but you can see a slight edge to some it that may become bothersome in certain circumstances if you want to be really anal.

The ironic thing is that I'm not fighting this these points because I think bokeh is very important, but because I think it isn't (or at least that its importance is greatly overstated and that the term is misused to the point that it could be considered harmful).

humberklog

charybdis wrote: »

I wasn't going to comment, but since you asked (before you edited your post):



I'm not really sure it evidences good control of depth-of-field. It's certainly shallow depth-of-field, although I don't think there's really much evidence of control other than making it as shallow as possible for that composition.


The ironic thing is that I'm not fighting this these points because I think bokeh is very important, but because I think it isn't (or at least that its importance is greatly overstated and that the term is misused to the point that it could be considered harmful).

Yeah good point but from my side of ignorance I'm always a bit impressed when someone does that really shallow stuff as I can't (never bother) to.

"Harmful"? How so? (Not a pedantic question but just a very curious one as I too hope to reach the dizzy heights of knowledge like FoxT and at some point become "improved" in my understanding).

cnocbui

charybdis wrote: »

That is true, but I still don't know what you think it proves.

I'm not surprised.

I was mostly posting to see if you absolutely, positively, with no exceptions, always had to get the last word in. You passed.

charybdis

humberklog wrote: »

Yeah good point but from my side of ignorance I'm always a bit impressed when someone does that really shallow stuff as I can't (never bother) to.

It's very easy. Focus on something quite close to the camera against a more distant background (preferably with purty lights and whatnot). Large apertures and longer focal lengths help, too.

humberklog wrote: »

"Harmful"? How so? (Not a pedantic question but just a very curious one as I too hope to reach the dizzy heights of knowledge like FoxT and at some point become "improved" in my understanding).

It just seems like a lot of people are caught up with the idea that shallow depth-of-field automatically makes a photograph good and they use (or subscribe to) the nebulous misconceptions of "bokeh" to try to lend legitimacy to the practise.

Don't get me wrong, I think there is a time & place for shallow depth-of-field, but nifty-fifty aperture-priority insta-art has really begun to grate on me.

I think it's a very useful thing to do when learning about photography, it just seems like people get stuck in that phase and it ends up making what could've been a good photographer (or photograph) worse due to their compulsion to have as shallow a depth-of-field as possible.

That said, I don't really think it's fair to constantly be critical of others' photographs, particularly if they're happy with them, but I do think criticising the misuse of certain terms and better explaining them can be instructive.

cnocbui wrote: »

I was mostly posting to see if you absolutely, positively, with no exceptions, always had to get the last word in.

Me too.

You passed.

Wait.

Crap.

(Also, does this mean you were saying silly things on purpose?)

humberklog

charybdis wrote: »

It's very easy. Focus on something quite close to the camera against a more distant background (preferably with purty lights and whatnot). Large apertures and longer focal lengths help, too.



It just seems like a lot of people are caught up with the idea that shallow depth-of-field automatically makes a photograph good and they use (or subscribe to) the nebulous misconceptions of "bokeh" to try to lend legitimacy to the practise.

Don't get me wrong, I think there is a time & place for shallow depth-of-field, but nifty-fifty aperture-priority insta-art has really begun to grate on me.

I think it's a very useful thing to do when learning about photography, it just seems like people get stuck in that phase and it ends up making what could've been a good photographer (or photograph) worse due to their compulsion to have as shallow a depth-of-field as possible.

That said, I don't really think it's fair to constantly be critical of others' photographs, particularly if they're happy with them, but I do think criticising the misuse of certain terms and better explaining them can be instructive.

Thanks for the tip on DOF but it's just not my thing.

Cracking answer for the rest as well too.

Oh and completely off topic (but the threads kinda rolling like that)...are you a boy or a girl?

FoxT

I think shallow DOF has its place, but I dont go running around looking for 'Bokeh'....So just went & shot these a few mins ago..



I think the reflections off the keys in the background is bokeh. It is an OOF highlight. Lots of other areas in the pic are oof , but they are not highlights.


In this one, I would regard the oof highlight on the bottle as Bokeh:



Am I on the right track with this? Or, is the entire oof areas on each pic 'Bokeh' ?

It occurred to me while I was shooting them that the no. of iris blades was completely unimportant - as shot wide open.

humberklog

FoxT wrote: »

I think the reflections off the keys in the background is bokeh. It is an OOF highlight. Lots of other areas in the pic are oof , but they are not highlights.

Bokeh's not about Thinking it's Bokeh but doing it with Bokeh, no?

It's moving in parrallels of consideration and empathy with both the fore and background, no?

humberklog

drift front
fore to bubblicious
and to front


I'm going Haiku
For le****su
moo moo.

charybdis

humberklog wrote: »

Thanks for the tip on DOF but it's just not my thing.

Cracking answer for the rest as well too.

Oh and completely off topic (but the threads kinda rolling like that)...are you a boy or a girl?

I'm male (although I can understand why you'd think otherwise, given my mythological namesake).

FoxT wrote: »

I think shallow DOF has its place, but I dont go running around looking for 'Bokeh'....So just went & shot these a few mins ago..

https://lh5.googleusercontent.com/_QUZCzGXHyzw/TVhq9U9ncWI/AAAAAAAAMqo/ucfLOfpibIg/s400/IMG_1127.JPG

I think the reflections off the keys in the background is bokeh. It is an OOF highlight. Lots of other areas in the pic are oof , but they are not highlights.


In this one, I would regard the oof highlight on the bottle as Bokeh:

https://lh5.googleusercontent.com/_QUZCzGXHyzw/TVhrJ-15qdI/AAAAAAAAMqs/90ONoKs94rY/s400/IMG_1129.JPG

Am I on the right track with this? Or, is the entire oof areas on each pic 'Bokeh' ?

It occurred to me while I was shooting them that the no. of iris blades was completely unimportant - as shot wide open.

I don't really think you're on the right track.

The out-of-focus highlights aren't bokeh, they're out-of-focus highlights.

It might help if you think of the term "bokeh" in a similar way to how you'd think of the term "colour rendition" (I'm not saying that they're directly related, just that the terms are used similarly). Lenses render colours differently: colour rendition is a characteristic of lens design. In the same way, lenses render out-of-focus areas of an image differently: rendering of out-of-focus areas is a characteristic of lens design.

You could kinda point to a specific portion of an image and say "that's colour rendition", and you wouldn't be entirely incorrect, but it would be a strange way to use the term and isn't really a meaningful statement.

In the same way, pointing to a specific portion of an image and saying "that's rendition of and out-of-focus area", or "that's bokeh", wouldn't be considered entirely incorrect, but it would be a similarly strange thing to say.

Bokeh is a property of a lens, not of an image.

humberklog wrote: »

drift front
fore to bubblicious
and to front


I'm going Haiku
For le****su
moo moo.

Bokeh is something
You probably should ignore
And focus elsewhere.

melekalikimaka

bokeh, not the most beautiful, but clearly defined...







imo

DaireQuinlan

melekalikimaka wrote: »

bokeh, not the most beautiful, but clearly defined...



imo

A response planned, but
'melekalikimaka'
takes up all the space

Promac

Bokeh is just the quality of the out of focus area in a shot. Is it out of focus, and does it look nice? If yes - nice bokeh. If no - not nice bokeh. It's well enough defined at this stage and the definition is hardly a subjective thing - sure, deciding if a specific shot has good or bad bokeh is subjective but the definition of bokeh itself isn't.

Wikipedia explains it best (as usual):

Bokeh is often most visible around small background highlights, such as specular reflections and light sources, which is why it is often associated with such areas.However, bokeh is not limited to highlights; blur occurs in all out-of-focus regions of the image.

cnocbui

charybdis wrote: »

(Also, does this mean you were saying silly things on purpose?)

At the end there, yes. I ceased being bothered enough to waste time countering casuistry.

For instance, you said:

There's a Pentacon 135mm f/2.8 lens that has 19 aperture blades, for example. Why would they put so much effort into building a lens for this expressed purpose, only to fall short on the number of blades?

In answer to my reply where I mentioned 'the law of diminishing returns'. My answer to your question would have been the same as that I had already given.

As for Zeiss. I couldn't be bothered with the long answer, but it would have had something to do with when did Zeiss design lenses for Hasselblads, when did the Japanese concept of Bokeh become more widely known in the west, and why do Zeiss now design a lens with 9 blades instead of 5?

Engineers tend not to put 9 wheels on cars when four will do, It would add unnecessary complication and cost. Engineers who design lenses would be no different.

You asked what the fact so many highly regarded lenses having high blade counts proves? Nothing except the self evident fact they don't have 5. One could wonder why that is though. Since you have been so keen to point out a lens can have 5 blades, we know there is unlikely to be a mechanical reason why all those mentioned have nearly double that number. Therefore, logically, given what we know about engineers, there is likely to be some other good reason. I'll make a wild unprovable guess that it might be related to optical performance.

You believe what you want to, and I shall do likewise.

jpb1974

FoxT

I don't see any Bokeh in the image above...

FoxT

cnocbui wrote: »

Engineers tend not to put 9 wheels on cars when four will do, It would add unnecessary complication and cost. Engineers who design lenses would be no different.

You are absolutely correct here - unfortunately, engineers have to do what Product Managers tell them to do!! I suspect that in many cases 7,8,9....19 blades are designed in for marketing purposes - ie 'this lens has 9 blades so therefore is better than the 5-bladed one'

This kind of thing happens all the time....

On cars, the trend is for alloy wheels with wide, low-profile tyres. This is not, in general, an optimal solution from an engineering or a cost point of view.

On compact cameras, you have all kinds of features that many people will never use (gimmicky in-camera editing functions etc) - and some features that are positively unhelpful (digital zoom), and some that are sub-optimal (pixel density too high, at the expense of high ISO performance ) for marketing purposes.

-FoxT

cnocbui

I fully agree, however... , one of my 9 bladed Zuikos was made in 1984. I certainly never came across any reference to bokeh until the late 90's and none of the marketing gumpff I have from the period makes any reference to blade count. The only reference was in the technical specs for lenses.

Maybe it was a very subtle understated Japanese thing where it was included for those in the know or they kept such references to the Japanese market literature and not the external market stuff because they thought it wouldn't be understood?

I haven't been shopping for lenses for a while, is it common for blade count to be touted in the marketing blurb these days?

FoxT

Blade count is not a headline feature, but it is not a 'small print' issue either. Lens reviewers mention it quite a bit, even going so far as to state whether the blades are rounded or not.

I did a good bit of photography in the 80's then went on an extended break...back then , I'd never heard of it. But the web has lots of references to it now. I have no idea when it emerged or where it came from, or why a Japanese word is used, etc.

mloc

I think Bokeh refers to the quality of the out of focus areas in the photo, not the extent of the DOF nor any compositional element of the photo.

From an optical point of view, focal length, aperture, diaphragm shape and even sensor size will all play their part on the final Bokeh quality. While most people will agree on specific cases of good and bad bokeh, it's still highly subjective and you can't really measure it.

Bokeh is most obvious where there are highly contrasting points of light in the background of a shallow DOF image. Here is an example of good bokeh (some might even call this "odd" bokeh, and the lens used is somewhat of Bokeh lover's staple):


anniina by Samuli Ikäheimo, on Flickr

Unusually wide apertures can also lead to very obvious Bokeh:


bubbling over by moaan, on Flickr

Promac

cnocbui wrote: »

I haven't been shopping for lenses for a while, is it common for blade count to be touted in the marketing blurb these days?

In the reviews about lenses yeah, certainly. More blades gives a more rounded appearance to the highlights in out of focus areas. 5 blades = pentagons while 9 blades (especially curved) = nice smooth circles like in mloc's examples.

charybdis

Promac wrote: »

Bokeh is just the quality of the out of focus area in a shot. Is it out of focus, and does it look nice? If yes - nice bokeh. If no - not nice bokeh. It's well enough defined at this stage and the definition is hardly a subjective thing - sure, deciding if a specific shot has good or bad bokeh is subjective but the definition of bokeh itself isn't.

Wikipedia explains it best (as usual):

Wikipedia
is great but not prescriptive.
Context is needed.

And, your description
Is at odds with the one in
Wikipedia.

cnocbui wrote: »

At the end there, yes. I ceased being bothered enough to waste time countering casuistry.

Fails to make a point,
tries to claim he was trolling
because he is mad.

cnocbui wrote: »

For instance, you said: In answer to my reply where I mentioned 'the law of diminishing returns'. My answer to your question would have been the same as that I had already given.

I do not think the
diminishing returns law
applies in this case.

It doesn't explain
the Minolta STF
having so few blades

when you consider
that it was over-designed
for bokeh bestness.

Surely such a lens
over-designed to this end
wouldn't skimp on blades.

Unless, the effect,
is greatly overstated,
of diaphragm shape.

The aperture blades'
strong influence on bokeh
is not established.

Nobody has shown
bokeh and aperture blades
are associated.

cnocbui wrote: »

As for Zeiss. I couldn't be bothered with the long answer, but it would have had something to do with when did Zeiss design lenses for Hasselblads, when did the Japanese concept of Bokeh become more widely known in the west, and why do Zeiss now design a lens with 9 blades instead of 5?

Engineers tend not to put 9 wheels on cars when four will do, It would add unnecessary complication and cost. Engineers who design lenses would be no different.

You asked what the fact so many highly regarded lenses having high blade counts proves? Nothing except the self evident fact they don't have 5. One could wonder why that is though. Since you have been so keen to point out a lens can have 5 blades, we know there is unlikely to be a mechanical reason why all those mentioned have nearly double that number. Therefore, logically, given what we know about engineers, there is likely to be some other good reason. I'll make a wild unprovable guess that it might be related to optical performance.

Many old lenses
contain more aperture blades
than any of those.

Many old lenses
contain less aperture blades
than any of those.

Have you considered
the reason for lots of blades
isn't for bokeh?

cnocbui wrote: »

You believe what you want to, and I shall do likewise.

Subjectivity
in reality along
with it in bokeh?

jpb1974 wrote: »

I'm not sure what it
is that you're referring to.
"Beating a dead horse."

Anyway, I think
"Tilting against the windmill"
is appropriate.

FoxT wrote: »

You are absolutely correct here - unfortunately, engineers have to do what Product Managers tell them to do!! I suspect that in many cases 7,8,9....19 blades are designed in for marketing purposes - ie 'this lens has 9 blades so therefore is better than the 5-bladed one'

This kind of thing happens all the time....

On cars, the trend is for alloy wheels with wide, low-profile tyres. This is not, in general, an optimal solution from an engineering or a cost point of view.

On compact cameras, you have all kinds of features that many people will never use (gimmicky in-camera editing functions etc) - and some features that are positively unhelpful (digital zoom), and some that are sub-optimal (pixel density too high, at the expense of high ISO performance ) for marketing purposes.

-FoxT

It so happens that
features are determined by
what will sell better.

If enough people
think more blades means more bokeh
they'll be catered to.

cnocbui wrote: »

I fully agree, however... , one of my 9 bladed Zuikos was made in 1984. I certainly never came across any reference to bokeh until the late 90's and none of the marketing gumpff I have from the period makes any reference to blade count. The only reference was in the technical specs for lenses.

Maybe it was a very subtle understated Japanese thing where it was included for those in the know or they kept such references to the Japanese market literature and not the external market stuff because they thought it wouldn't be understood?

I haven't been shopping for lenses for a while, is it common for blade count to be touted in the marketing blurb these days?

It's almost as if
number of blades and bokeh
are unrelated.

Many non-Japan
lens manufacturers made
lenses with more blades.

FoxT wrote: »

Blade count is not a headline feature, but it is not a 'small print' issue either. Lens reviewers mention it quite a bit, even going so far as to state whether the blades are rounded or not.

I did a good bit of photography in the 80's then went on an extended break...back then , I'd never heard of it. But the web has lots of references to it now. I have no idea when it emerged or where it came from, or why a Japanese word is used, etc.

The reality
is that nobody has shown
strong links between them.

mloc wrote: »

I think Bokeh refers to the quality of the out of focus areas in the photo, not the extent of the DOF nor any compositional element of the photo.

Saying "quality"
without qualification
is just meaningless.

Although, I would say
I broadly agree with much
that is in this post.

mloc wrote: »

From an optical point of view, focal length, aperture, diaphragm shape and even sensor size will all play their part on the final Bokeh quality. While most people will agree on specific cases of good and bad bokeh, it's still highly subjective and you can't really measure it.

Aspects of bokeh
can be measured easily
and then classified.

Sensor size has no
affect bokeh, but it does
affect depth-of-field.

Shallow depth-of field
is not the same as bokeh.
You are conflating.

RE: preferences,
There's no accounting for taste,
in bokeh or not.

mloc wrote: »

Bokeh is most obvious where there are highly contrasting points of light in the background of a shallow DOF image. Here is an example of good bokeh (some might even call this "odd" bokeh, and the lens used is somewhat of Bokeh lover's staple):

anniina by Samuli Ikäheimo, on Flickr

Unusually wide apertures can also lead to very obvious Bokeh:

bubbling over by moaan, on Flickr

Actually, both
evidence "bad", "nisen", or
"hard edged" bokeh.

That's not to say that
they're unpleasant images.
But they are not "good".

Promac wrote: »

In the reviews about lenses yeah, certainly. More blades gives a more rounded appearance to the highlights in out of focus areas. 5 blades = pentagons while 9 blades (especially curved) = nice smooth circles like in mloc's examples.

Again, I will stress
this ain't the same as bokeh
or much related.

Kintarō Hattori

Why can't everyone do the gentlemanly thing and just agree to disagree. Otherwise you'll all be here this time next year................ or until the mods lock it from the frustration that it's surely causing!

Fajitas!

Kintarō Hattori wrote: »

Why can't everyone do the gentlemanly thing and just agree to disagree. Otherwise you'll all be here this time next year................ or until the mods lock it from the frustration that it's surely causing!

Oi! Don't be stifling important discussion.

charybdis wrote: »

...

Chary wins.

Promac

charybdis wrote: »

Self-indulgent twaddle

Trollin.

AnCatDubh

Kintarō Hattori wrote: »

or until the mods lock it from the frustration that it's surely causing!

(I think this thread may have run its course - ding-de-ding-ding-ding-ding-ding-ding-ding)

charybdis

AnCatDubh wrote: »

(I think this thread may have run its course - ding-de-ding-ding-ding-ding-ding-ding-ding)

I really don't see
why you'd close this thread so soon.
It just seems a waste.

People are learning
discussing photography.
One guy is butthurt.

humberklog

Five cats no frogs
banjo tunes
thread remain

AnCatDubh

charybdis wrote: »

I really don't see
why you'd close this thread so soon.
It just seems a waste.

People are learning
discussing photography.
One guy is butthurt.

em, but you posted to a c-l-o-s-e-d thread...... you must have jedi like powers sir to transverse the ultimate close thread function of vbulletin. I bow to your greatness.

anyhow wasn't responding to you :P

charybdis

AnCatDubh wrote: »

em, but you posted to a c-l-o-s-e-d thread...... you must have jedi like powers sir to transverse the ultimate close thread function of vbulletin. I bow to your greatness.

anyhow wasn't responding to you :P

It was not you I
was referring to. These are
not the droids you seek.

cnocbui

This would be an example of what I consider pleasing bokeh without in any way involving highlightes.