Archived posting to the Leica Users Group, 2000/08/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]on 27/8/00 11:07 pm, Mark Rutledge at markrut@ticnet.com wrote: > Maybe bokeh has more to do with the "art" aspect of photography rather than > the technical side. Emotion vs quantifiability. Images (painting, photos..) > can move us in a way we cannot describe...beauty isn't measurable. Just a > guess! I think bokeh is pretty measurable. Just no-one measures it yet. It's pretty simple. You just look at the way the lens renders out of focus point sources at various distances. You measure the light intensity from the centre of the point outwwards along a radius. This spread function defines the bokeh of the lens, to a VERY good first approximation, since any image cam ne considered as a collection of point sources. That's it. Period. It's not difficult, complicated or airy fairy. The corollary of this is that a simple test for a lens' bokeh, as anyone who cares about it knows, is to look at out of focus specular highlights. Diffuse circles = creamy bokeh. Hard edged circles = sharp transitions in the out of focus areas (is there a word for this?). Donut shapes (bright rings) = pronounced Ni-Sen bokeh, very painterly and textural, like the lux 50. You don't care about bokeh? Fine. But my point of view is that a photographer should be in charge of every element of his/her craft. Grain, tonality, sharpness, bokeh and so on. Of course everyone knows the picture comes first. But photography is a craft as well as an art. Why do I care? I just developed twenty five rolls. Pretty much all of it was shot wide open on either the 35/1.4 or the TE 90/2.8. I have way more stuff out of focus than in focus. Thank God for nice bokeh! - -- Johnny Deadman http://www.pinkheadedbug.com