Archived posting to the Leica Users Group, 2001/07/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Wed, 11 Jul 2001, Rodgers, David wrote: > Why don't we just call it blur? Fewer letter and most English speaking > persons understand exactly what it means. Plus, we learn how to pronounce it > in grammar school. > > Giving the blurred area of a photograph a fancier title doesn't make it more > important. The out of focus portions of my images are that way so they don't > distract from what IS important. But bokeh is not used exactly as "blur". Bokeh is _how a specific lens renders the out of focus areas_. You cannot talk about the "blur of a lens", can you? > Next thing you know Photoshop will come up with a Gaussian Bokeh tool. It'll > do exactly the same thing as the Gaussian Blur tool. They'll charge more for > the program and people will write books on how to use the Gaussian Bokeh > more effectively. Actually, it is an interesting fact that gaussian blur is the easiest thing to simulate when doing synthetic images, and a hard thing to get when designing a sharp, aberration-free lens. A 3D computer graphics rendering program that can do depth of field effects will usually render the blurry parts in a very soft way, like a lens with "good" bokeh. A few months ago I introduced the concept of bokeh to one of my friends, who is one of the architects of the rendering program we use here at PDI (we rendered _Shrek_ with it), and suggested he simulated realistic bokeh in his renderer. Take a look here: http://www.flarg.com/bokeh.html You can put the "lens" out of focus, and modify the bokeh characteristics. The gaussian curve is what we'd like in our physical lenses. The "V" gives what you'd get with a mirror lens. BTW, in the description, when he says "similar to a Leica lens", he actually means "an older, uncorrected Leica lens". I don't really think the bokeh of modern lenses is better than that of older ones. j - -- - --------------------------------------------------------------------------- Juan J. Buhler | Sr. FX Animator @ PDI | Photos at http://www.jbuhler.com - ---------------------------------------------------------------------------