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Bokeh out of focus images

G

Guest

Much has been said about "bokeh", or out of focus images. The 11/96 Popular Photo test report says that the current Elmar 50 2.8 has a 6-bladed diaphragm, previous ones had 9-bladed and more. I have an older SM 50 2.8 Elmar that has a 15-blade diaphragm. PP says that many claim more blades make for a rounder diaphragm opening with better bokeh.
Also, Minolta in a brochure dating from 2000, states that some of their lenses are made with 7 or 9 blade diaphragms which, when closed down 1.5 stops, produce a circular aperture to improve bokeh.
It seems that this may be a way that someone could determine how a lens will do in this regard.
 
G

Guest

>The expensive Minolta P&S camera has apertures that are different sized >circular holes drilled in metal. I would like to see the bokeh from this >camera.
 
G

Guest

Bokeh is influenced by several factors, but what matters most is the distribution of light intensity across the circle of confusion. If the light intensity is stronger in the center of the CoC, you get "good" bokeh. Greater light intensity at the edge of the CoC gives you "bad" bokeh. An extreme ex&le of "bad" bokeh is a mirror lens, which has no light at all in the center of the CoC.
 
G

Guest

I agree with this message. I have a 12 blade diaphragm in a 1935 Schneider lens and the "bokeh" is excellent. i think there is a direct relationship between good bokeh and a large nuber of diaphragm blades. The pre war lenses had better bokeh compared to the post war ones because of this
 
G

Guest

> An extreme ex&le of "bad" bokeh is a mirror lens, > which has no light at all in the center of the CoC. =================================================================

OOOHHH Doug ! Do you mean you don't like "doughnuts" ?
 
G

Guest

I have a 12 blade diaphragm in a 1935 Schneider lens and the "bokeh" is excellent. i think there is a direct relationship between good bokeh and a large nuber of diaphragm blades. The pre war lenses had better bokeh compared to the post war ones because of this.
 
G

Guest

<I>i think there is a direct relationship between good bokeh and a large number of diaphragm blades</I>

This does not account for lenses with "bad" bokeh at full aperture.

<I>OOOHHH Doug ! Do you mean you don't like "doughnuts" ? </I>

Unfortunately I like eating them too much ;-) In my pictures, yecchh!
 
G

Guest

> i think there isa direct relationship between good bokeh and a large nuber of diaphragm blades. The pre war lenses had better bokeh compared to the post war ones because of this ================================================================= No. This is incorrect. What you call "good bokeh" is actually dependent on the uncorrected aberations in a lens. As uncorrected abberations are reduced, the out of focus areas of the image become sharper and more contrasty, ie, harsher, or "bad bokeh".
 

garth

Active Member
hello all!
staying up late here surfing this great site, reading on people's thoughts on bokeh.

just got a 90mm tele elmarit (skinny) today which i'm very excited about. little nervous about this particular lenses bokeh, does anyone know why leica made the aperture leafs take on a 'star' pattern? what's peculiar is that wide open and closed the leafs make a very perfect circle. between at f8 the star pattern is very apparent.

i've only seen internet pics that try to illustrate "ratty" bokeh, but the negs i shot today didn't look so bad.

curious to know anyone's thoughts...

garth
 

ted_grant

Member
Garth said:
>>staying up late here surfing this great site, reading on people's thoughts on bokeh.

just got a 90mm tele elmarit (skinny) today which i'm very excited about. little nervous about this particular lenses bokeh, does anyone know why leica made the aperture leafs take on a 'star' pattern? what's peculiar is that wide open and closed the leafs make a very perfect circle. between at f8 the star pattern is very apparent.

i've only seen internet pics that try to illustrate "ratty" bokeh, but the negs i shot today didn't look so bad. <<<<<<<<

Garth mon ami,

My advice after 50 plus years of professional use of Leica gear.......... forget the bohek and make sure the main content of the picture is in sharp focus and interesting. And nobody but techie gear heads will ever look at the OOF backgrd. :)

ted
 

garth

Active Member
i'm thinking you're right : ) shot some 'workshops' with it today and loved it. just have to get a second body so i don't have to fumble with trading between the 35mm lens.

with this combo i didn't feel i was missing my 50mm, which was kinda alright. three gets to be a lot of cameras to think with. this is also the combination that steve mc curry works with. if not a nikon 85 then maybe a 105.

i'll have to post some pics.

ciao,
garth
happy.gif
 
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