thanks - I had gotten most of that by reading in to the posts, but not so
clear. Is "bokeh" a made-up word or does it have real language origins?
"John A. Lind" wrote:
> Bokeh:
> While many concern themselves with what *is* in focus, bokeh is about what
> is *not* in focus. As important as contrast and resolving power is to a
> lens, its "bokeh" or how it handles what is out of focus is important also
> if you make use of a shallow "Depth of Field" for slectively focusing on
> your subject.
>
> Theoretical aspects of focus and what can go wrong:
> An out of focus point of light is theoretically a "circle of confusion."
> That is, it turns into a fuzzy circle. The more out of focus, the bigger
> the circle. Think of two cones, point-to-point. When the point is in
> exact focus, the film plane is where the two light cones meet and you get a
> point on the film. Focused in front or behind the light point, you get a
> circle with fuzzy edges and reduced contrast.
>
> No lens is perfect, and its "bokeh" can be different with points of light
> closer and farther the exact focus distance. One of the imperfections can
> be "coma" where the fuzzy circle has a small tail on it like the
> punctuation mark it is named after. A good lens design (and a lens in good
> condition) will not have "coma." Another is the circle taking on the shape
> of the aperture blades. The f/1.4 and f/1.2 50mm Zuikos (along with a few
> other of the faster [more expensive] primes) have eight blades. The f/1.8
> 50mm and most of the primes have six blades. If, instead of a fuzzy circle
> you see a fuzzy hexagon or octagon, this is what has happened. Yet another
> is not having a soft fuzzy edge to the "circle of confusion", but a sharp
> harsh one.
>
> All these things (and perhaps more) contribute to a lens' "bokeh." Bokeh
> is more generally more important with a long telephoto than it is with a
> super wide-angle, as you will likely encounter portions of your image out
> of focus more often with a long telephoto than with a super wide-angle. It
> is also important with macro work which often has very shallow depth of
> field. These are generalizations. If you do any photography which has
> portions of the image out of focus, knowing the bokeh of your lenses (wide
> open versus stopped down, in front of versus behind the focus distance,
> etc.) can help you create a better image in composing it beginning with
> lens selection (if you have a choice).
>
> -- John
>
> At 02:19 6/19/00 , Wayne wrote:
> >Am relatively new to the list, and recently back to my OMs (3 plus 10
> >lenses) after leaving them on the shelf for about fifteen years. They
> >still work great - its me who is a little rusty.
> >
> >Saw "Spiratone" listed in a post. What ever happened to them? Did they
> >become another company or just fade away. Aside from a lot of low cost
> >"juncque" they had a few nifty tools and accessories for close up work.
> >
> >And, please, what he heck is the specific definition and origin of
> >"bokeh" I have surmised the general meaning, but am still curious.
> >
> >Thanks,
> >
> >Wayne
> >
> >
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>
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