wide open

[nemjo]

Hi all,

I have a possible silly question about lenses.
I often read about significance of number of diaphragm blades, and thought it understand. More blades, the more circular iris - when stopped down.
And recently again on LL that how nice bokeh the 50/1.2 Nikkor has wide open for it's nine blade.
But how does it matter wide open?

nemjo

 

[mfogiel]

It doesn't.

 

[nemjo]

This was my first (few) thought(s) too.

But :

"This lens sings its most beautiful song wide open, where the combination of ultra-shallow depth of field, lovely boke due to its nine blade shutter, ...."

and this is far not the first interpretation on fast lenses I've read.
So I'm still puzzled...

nemjo

 

[FrankS]

When wide open, the aperture blades/shape does not come into play.

 

[Elektrojänis]

"This lens sings its most beautiful song wide open, where the combination of ultra-shallow depth of field, lovely boke due to its nine blade shutter, ...."

Looks a lot like it's just written by somebody who really doesn't understand. I've seen something like this several times too.

The shape of the aperture is a bit overrated feature when it comes to the quality of the boke/bokeh. It mainly affects the shape of highlights. Many other things affect the overall boke quality (smoothness or whatever) more.

 

[mdarnton]

Simply put, it's a MIRACLE that the 9 leaves impart, even when they're not present. I have seen "beautiful" bokeh claimed for some of the most gawd-awful jittery stuff or backgrounds that look like clusters of sharp-edged smoke rings that I wouldn't take anyone's word for anything on the topic. Go with what you see and like, not what you read.

 

[btgc]

"due to its nine blade shutter, ...."

I wouldn't bother reading any further, frankly. Technical side can kill art not only when it dominates but also when it is absent.

Shutter, sigh.

 

[ruby.monkey]

Well they're talking about the 50mm f/1.2 AIS-Nikkor, so even 'This lens sings its most beautiful song wide open' is suspect.

 

[Matus]

I would say that while number of aperture blades does (somewhat) influence the smoothness of OOF image part - it is a distant second to lens design and conditions (means = what are the objects that are OOF, what is the light).

I had an olympus XA - it had 4(!) aperture blades - these only become visible when more stopped down around spot light sources or reflections.