Is Gaussian blur ideal bokeh?

[nickzou]

Obviously there's a personal taste element to this question. Personally, that "distracting" double-lined chunky bokeh from cheap lenses is actually the kind of bokeh that is pleasing to my eye but I think there is a general idea of what good bokeh is. It seems that good bokeh is really really smooth. If that is the case, isn't Gaussian blur the ideal bokeh maker? It evenly distributes and blurs the image (or a section of the image) in all directions. Note, I'm not necessarily saying that bokeh should be simulated in post-processing but I am wondering if that good bokeh that is often sought after in lenses is the same effect as Gaussian blur.

 

[raphaelaaron]

I think what you are referring to is Lens blur? Regardless they simply won't do. I think we're still at the point where creating a truly good bokeh from nice glass is still hard to reproduce through photoshop.

 

[MLeeK]

Gaussain blur is gaussain blur. It's a blur. Bokeh is the out of focus points of light in the image.
Scroll down just a bit on this page and there are examples of good and bad bokeh. Bokeh

 

[Rephargotohp]

You can't simulate the effect of aperture shape with Gaussian Blur and then again why do you even neeed to simulate something

 

[nickzou]

Gaussain blur is gaussain blur. It's a blur. Bokeh is the out of focus points of light in the image.
Scroll down just a bit on this page and there are examples of good and bad bokeh. Bokeh

Yeah... it says good bokeh is ideal Gaussian distribution.

 

[nickzou]

You can't simulate the effect of aperture shape with Gaussian Blur and then again why do you even neeed to simulate something

According to the Ken Rockwell article, that is bad bokeh. Good bokeh is supposed to be completely smooth, so lacking the distinctive shape of the aperture blades. Too bad because that kind of 'rough' bokeh is what I like.

EDIT: Actually, I think part of why I like that 'rough' imperfect bokeh look is because it can't be simulated via software. It looks uniquely like something that came out off of a camera.

 

[MLeeK]

You'll often get that octagonal shape when you are using a cheaper lens. They have less blades in them with makes the aperture have sides instead of being perfectly round.

You need to have round points of light that are smooth across the whole point-not brighter on the edges or brighter in the center.
You can't simulate bokeh with gaussain blur alone. You have to have the "sparkle" in it.

 

[nickzou]

You'll often get that octagonal shape when you are using a cheaper lens. They have less blades in them with makes the aperture have sides instead of being perfectly round.

You need to have round points of light that are smooth across the whole point-not brighter on the edges or brighter in the center.
You can't simulate bokeh with gaussain blur alone. You have to have the "sparkle" in it.

And that's not part of the what you would "want" from bokeh? I thought it was just a limitation of current lens design that it cannot render lights as smoothly as everything else that is out of focus in the same scene. Is sparkly round bokeh balls not just as distracting any other out of focus element that isn't rendered perfectly smooth?

 

[o hey tyler]

I guess if you like what bad bokeh looks like, you'll save a lot of money on lenses. And probably lose a lot of clients. But that's not the point, the bokeh is ROUGH TO THE CORE.

 

[nickzou]

I guess if you like what bad bokeh looks like, you'll save a lot of money on lenses. And probably lose a lot of clients. But that's not the point, the bokeh is ROUGH TO THE CORE.

Well I don't have any clients... (And I'm not even sure if I ever do)

And the times I've been assistants to photographers, none of the clients seemed worried about bokeh. More about sharpness and proper exposure.

 

[raphaelaaron]

Bokeh is more for photographers to respect, rather than your everyday client. But that doesn't rule out that a client doesn't notice the smooth and shallow DOF and how it makes a picture look. They see it as being a "good" picture. We probably might see it as a mix of aperture, focal length and lens blades.

To some extent, you'll lose clients to other photographers who have what appears to clients as "better looking pictures" because they invested in better glass.

 

[nickzou]

Bokeh is more for photographers to respect, rather than your everyday client. But that doesn't rule out that a client doesn't notice the smooth and shallow DOF and how it makes a picture look. They see it as being a "good" picture. We probably might see it as a mix of aperture, focal length and lens blades.

To some extent, you'll lose clients to other photographers who have what appears to clients as "better looking pictures" because they invested in better glass.

That seems more like an artificial construct though. At least in my mind, like art trends. See, growing up I wasn't into or knowledgeable about photography but what I did have in my mind was the lens flare, maybe the technology just didn't exist to reduce flares and ghosting at the time but I just came to accept it as part of that "photographic look", to my surprise now that I am interested, I find that the lens flare is something to be rid of; something not to be desired. But because of how... I saw photography as a child, the lens flare has always seemed "right" to me. And maybe that's where I get my idea of rough bokeh looking more "real".

What I've heard about bokeh is that it is not supposed to be distracting but for some reason the bokeh light balls are the exception to this rule. Perfectly round, BUT sharp bokeh balls are desired. But that seems just as "distracting" as rough bokeh. All of this is to say "what is proper" or "what is right" at the very least in terms of bokeh seems arbitrary; subject to trend and taste rather than having any real aesthetical value.

 

[enzodm]

Gaussain blur is gaussain blur. It's a blur. Bokeh is the out of focus points of light in the image.
Scroll down just a bit on this page and there are examples of good and bad bokeh. Bokeh

Yeah... it says good bokeh is ideal Gaussian distribution.

... according to mathematicians. The next sentence tells "This is one area in which physics doesn't mirror what we want artistically.".

If your background is flat at the same distance from camera and subject, you may grossly simulate blur with gaussian distribution, but if distance is variable, you have to modify distribution parameters for each distance so... it's not just gaussian distribution. You need a distance map or so.
By the way, from what I understood, it is difficult to have the same bokeh in foreground as well as background, due to the way aberration corrections are done.

Bokeh may be a component of the picture with some sense. Mathematically perfect bokeh gives you some effect, some other kind will give you some other effect. Just use it if you can choose, and minimize bad looking effects if you can. You may as well be glad of what you have - always the best way to live well without problems

 

[enzodm]

All of this is to say "what is proper" or "what is right" at the very least in terms of bokeh seems arbitrary; subject to trend and taste rather than having any real aesthetical value.

like flare, it may just be a tool. Having flare by chance is a bad thing. Having bad bokeh by chance is a bad thing. Using them with awareness may produce nice things.
Regarding the aestethical value, I hope Derrel with cross this thread, because he will give you an idea of the connection between bokeh and japanese picture -it is not just a technical question, but has to do with the value of "background".

 

[nickzou]

All of this is to say "what is proper" or "what is right" at the very least in terms of bokeh seems arbitrary; subject to trend and taste rather than having any real aesthetical value.

like flare, it may just be a tool. Having flare by chance is a bad thing. Having bad bokeh by chance is a bad thing. Using them with awareness may produce nice things.
Regarding the aestethical value, I hope Derrel with cross this thread, because he will give you an idea of the connection between bokeh and japanese picture -it is not just a technical question, but has to do with the value of "background".

lol that sounds good. I look forward to that.