There's more to bokeh than meets the eye... :P (duh?)
One very unscientifical observation that I (at least think) I have made is that lenses optimized for high MEDIUM resolution values (20lpm, or what some people call "fine contrast") seem to have a more gaussian spread back-bokeh than lenses optimized for maximum fine resolution (40lpm+), who seem to be more prone to display ni-sen bokeh.
My guess is that this relates to HOW the lens designer corrected for spherical aberations:
High contrast means an even spread of a high percent of the total light-energy on a slightly larger than optimal best-focus c-o-c and a very small amount/big area of wider spread stray rays - compared to the high resolution version which would be to focus the best-focus c-o-c to a finer point, but accept a higher percentage of stray rays spread over a larger area (lower wide-area contrast).
This would also concur with the widely spread opinion that many of the 50-70's best lenses have a softer and less distracting back bokeh. Today a maximum fine resolution contrast seems to be prioritized in the design process of high-end lenses.
Do you guys think I'm totally off mark here? Opinions and educated guesses are more than welcome...
I'm firmly in the "smoother is better" camp, what some people consider "interesting" bokeh I see as "distracting" bokeh. I prefer objects out of focus to be just that - out of focus. I don't want them to be strong parts of my composition. If I did I would choose a deeper DOF or focus differently. But - I realize that this is personal preference, I also prefer electronic music to experimental Jazz. This does in no way mean that jazz isn't "good music" per definition, it just means that I PERSONALLY prefer Depeche Mode to ....(fill in some name here)
Pure facts (water is wet when at room temperature) and opinions (water is disgusting) are, and should always be two very separate things!
theSuede wrote:
There's more to bokeh than meets the eye... :P (duh?)
One very unscientifical observation that I (at least think) I have made is that lenses optimized for high MEDIUM resolution values (20lpm, or what some people call "fine contrast") seem to have a more gaussian spread back-bokeh than lenses optimized for maximum fine resolution (40lpm+), who seem to be more prone to display ni-sen bokeh.
My guess is that this relates to HOW the lens designer corrected for spherical aberations:
High contrast means an even spread of a high percent of the total light-energy on a slightly larger than optimal best-focus c-o-c and a very small amount/big area of wider spread stray rays - compared to the high resolution version which would be to focus the best-focus c-o-c to a finer point, but accept a higher percentage of stray rays spread over a larger area (lower wide-area contrast).
This would also concur with the widely spread opinion that many of the 50-70's best lenses have a softer and less distracting back bokeh. Today a maximum fine resolution contrast seems to be prioritized in the design process of high-end lenses.
Do you guys think I'm totally off mark here? Opinions and educated guesses are more than welcome... ...Show more →
I think your totally correct.
theSuede wrote:
I'm firmly in the "smoother is better" camp, what some people consider "interesting" bokeh I see as "distracting" bokeh.
Same here...These forums have been inundated with Minolta 58mm f1.2 Rokkor samples lately and most have extremely distracting backgrounds because the though the Rokkor is very sharp WO it is unable to blur out OOF highlights like lenses that are slightly softer WO such as my Canon FL 55mm f1.2.
theSuede wrote:
I prefer objects out of focus to be just that - out of focus.
Same here!
theSuede wrote:
I don't want them to be strong parts of my composition. If I did I would choose a deeper DOF or focus differently. But - I realize that this is personal preference, I also prefer electronic music to experimental Jazz.
You are not alone...I'll take Kraftwork over Dizzy Gillespie any day!
From the sample pictures I've seen on this forum, I'd say that of Volna-9 was the best one, if smooth bokeh is the name of the game.
Too bad it's only f/2.8
My idea of bokeh incorporates the notion that the background should not distract from the subject. So I agree with Alf.
Some people like what I consider distracting bokeh: distinct highlights, swirlyness etc. But I think these people have gone beyond the subject in a way I never intend to. And I think it is these people who have perpetuated the idea of bokeh being subjective, only because they don't relate subject and background like normal people: to them subject and background are not a harmony but the same note on different octaves. I suspect that these people are left-handed and use Brut 33 deodorant: decidedly sinister, in fact.
One of my theories is that their brains are upside down, my other theory is that they are made of porridge. But there is a difficulty in establishing the truth.
the whole premise that one physical/optical effect is good and another bad seems a bit weird imho.. But. .. Since we endlessly discuss and debate sharpness and all the other derivative topics, why not make subjective value judgments, and have good and bad blurry bits too? Works for me..
The person who gets to define the terms gets to win the most arguments
BTW can anyone tell me how to pronounce feng shui ?
. kennmon wrote:
my poor, poor thread.
Looks like I'm too late to jump in on the linguistics topic. Too bad, some of my favorite discussions around here. Anybody know of any amateur linguistics forums?
Thanks Dmitry for that flickr link. Looking at the direct comparison shots between the Rokkor and the Canon 55, the Rokkor actually draws the background smoother than the Canon, contrary to a lot of claims around here.
But i have to admit that rokkor that i have converted to sigma sd14 also is completely different from the same on 5D, it is more creamy and softer overall on open f - and focusing is harder because you miss it very easy - optimal f is f2 on crop body
f2
b/w is superb
Alf, the second shot (the cat) may have exceptionally harsh bokeh, but it works, doesn't it? It adds character to what would otherwise be a predictably ho-hum shot. (I wonder what the lens is. It's probably not a lens that one would ever associate "good bokeh" with.)
The shot that you link to may have "better" bokeh, but it also lacks character. No offence intended, of course. As we know, "good" bokeh can be scene-specific just as much as it can be lens-specific.
the whole premise that one physical/optical effect is good and another bad seems a bit weird imho.. But. .. Since we endlessly discuss and debate sharpness and all the other derivative topics, why not make subjective value judgments, and have good and bad blurry bits too? Works for me.. 
