[quote name='PuxaVida' timestamp='1299497127' post='6568']
It's strange that, we get away from the content and focus on language problems. I'm not sure if I used wrong expressions (within the context) and sorry for any inconveince. But apart from language issues, there's still no "I did not understant what you are saying" coming to me. And to complete my knowledge regarding bokeh, I will insist on the verification of my following statement:
To my knowledge, the amount of blur is different at a particular image within the distance from subject to background. Consider an image taken @ f/1.4. The amount of blur in 10cm distance from subject will be different than the amount of blur in 40m distance (given that both are OOF). If we close the aperture, the blurred range mentioned will be changing (will be shifted towards infinity) but the difference in the amount of blur will still be there (though, will be very less, almost not visible in the resulting image). In other words, the blur in nearer OOF area is less than the blur in distant OOF area. And this has an effect on smoothness of the color transitions (in near vs. distant OOF planes). Because closing or opening the aperture has an effect on results of the spherical aberrations.
So, I was asking to BC and now to you to explain me if I'm wrong. Then maybe I can have the opportunity to correct myself. But, please do not change the subject by pointing out linguistic problems concerning technical explanations. Language is a tool for communication, and every tool can be fixed, but the content is essential.
Serkan
[/quote]
You are not wrong about the AMOUNT of "blur" at all. But talking about bokeh is not about talking about the amount of blur, it is about the character of the OOF areas.
Good bokah, pleasant bokeh, is not about HOW blurry things get, it is about how the blur gets "rendered". And this has to do with the optics themselves, not with distances to subjects or a highlight here and there. So when we/I talk about a lens having better/smoother/more pleasant/creamier bokeh, it is not that the lens, compared to other lenses with the same focal length, shooting at the same subject/background distance, produces more blur. It is that the blur, the way it is rendered, is nicer.
Only that.
So, yes you are right that the shooting distance varies the amount of blur in OOF areas. And no, that has nothing to do with good or bad bokeh.
A very good example of a lens with unattractive/busy/bad bokeh is the Nikon AF-S 35mm f1.8 DX.
Take a look at how the background here is very restless, almost vibrating:
http://www.kenrockwell.com/nikon/images1/35mm-f18/DSC_8339-bad-bokeh-ryan.jpg
As you see, there is not a lot of blur. But the character of the blur is very unattractive. That is what we use the term "bokeh" for, describing the character of the blur, not the amount.
of course, the more you blur (shooting distance), the less obvious bad bokeh becomes.
More examples of the same lens:
http://farm1.static.flickr.com/110/4559911104_1df24a6953_b.jpg
http://farm5.static.flickr.com/4064/4499941927_f9ea922f16_b.jpg
Of course, you can avoid not so nice bokeh to show up. You vary/adjust shooting distance and DOF. That is just part of learning your gear.
Or you choose lenses with have a nicer bokeh character.
It's strange that, we get away from the content and focus on language problems. I'm not sure if I used wrong expressions (within the context) and sorry for any inconveince. But apart from language issues, there's still no "I did not understant what you are saying" coming to me. And to complete my knowledge regarding bokeh, I will insist on the verification of my following statement:
To my knowledge, the amount of blur is different at a particular image within the distance from subject to background. Consider an image taken @ f/1.4. The amount of blur in 10cm distance from subject will be different than the amount of blur in 40m distance (given that both are OOF). If we close the aperture, the blurred range mentioned will be changing (will be shifted towards infinity) but the difference in the amount of blur will still be there (though, will be very less, almost not visible in the resulting image). In other words, the blur in nearer OOF area is less than the blur in distant OOF area. And this has an effect on smoothness of the color transitions (in near vs. distant OOF planes). Because closing or opening the aperture has an effect on results of the spherical aberrations.
So, I was asking to BC and now to you to explain me if I'm wrong. Then maybe I can have the opportunity to correct myself. But, please do not change the subject by pointing out linguistic problems concerning technical explanations. Language is a tool for communication, and every tool can be fixed, but the content is essential.
Serkan
[/quote]
You are not wrong about the AMOUNT of "blur" at all. But talking about bokeh is not about talking about the amount of blur, it is about the character of the OOF areas.
Good bokah, pleasant bokeh, is not about HOW blurry things get, it is about how the blur gets "rendered". And this has to do with the optics themselves, not with distances to subjects or a highlight here and there. So when we/I talk about a lens having better/smoother/more pleasant/creamier bokeh, it is not that the lens, compared to other lenses with the same focal length, shooting at the same subject/background distance, produces more blur. It is that the blur, the way it is rendered, is nicer.
Only that.
So, yes you are right that the shooting distance varies the amount of blur in OOF areas. And no, that has nothing to do with good or bad bokeh.
A very good example of a lens with unattractive/busy/bad bokeh is the Nikon AF-S 35mm f1.8 DX.
Take a look at how the background here is very restless, almost vibrating:
http://www.kenrockwell.com/nikon/images1/35mm-f18/DSC_8339-bad-bokeh-ryan.jpg
As you see, there is not a lot of blur. But the character of the blur is very unattractive. That is what we use the term "bokeh" for, describing the character of the blur, not the amount.
of course, the more you blur (shooting distance), the less obvious bad bokeh becomes.
More examples of the same lens:
http://farm1.static.flickr.com/110/4559911104_1df24a6953_b.jpg
http://farm5.static.flickr.com/4064/4499941927_f9ea922f16_b.jpg
Of course, you can avoid not so nice bokeh to show up. You vary/adjust shooting distance and DOF. That is just part of learning your gear.
Or you choose lenses with have a nicer bokeh character.