Noctitron: Out of Round Cat's Eye Bokeh

Started 6 months ago | Discussions thread
Bob Tullis
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Re: Noctitron: Out of Round Cat's Eye Bokeh
In reply to jhinkey, 6 months ago

jhinkey wrote:

Bob Tullis wrote:

ApertureAcolyte wrote:

Why does the lens have this characteristic?

Usually this syndrome occurs from stuck aperture blades...

It's an optical aberration called coma. Here's a LensTip article that explains that and the rest of the "7 Deadly Abberations"

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...Bob, NYC
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"Well, sometimes the magic works. . . Sometimes, it doesn't." - Chief Dan George, Little Big Man
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Not according to:

http://www.zeiss.com/c12567a8003b8b6f/embedtitelintern/cln_35_bokeh_en/$file/cln35_bokeh_en.pdf

"At the edge of the photo iris images are also altered by vignetting if the light cones going to the edge of the photo at wide apertures are intersected by front or rear parts of the lens barrel or by the limited diameter of rear and front elements:"

Page 31. Mechanical vignetting of the light cone . . .

thank you, John.  

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...Bob, NYC
http://www.bobtullis.com
http://www.flickr.com/photos/bobtullis/
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"Well, sometimes the magic works. . . Sometimes, it doesn't." - Chief Dan George, Little Big Man
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 Bob Tullis's gear list:Bob Tullis's gear list
Olympus E-M1 Olympus M.Zuiko ED 75-300mm 1:4.8-6.7 II Rokinon 7.5mm 1:3.5 UMC Fisheye CS Voigtlander Nokton 17.5mm F0.95 Aspherical Olympus 12-40mm F2.8 +18 more
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