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f/0.72


Lindolfi

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The hunt for faster and faster lenses continues! Today I found a lens with an aperture of f/0.72. It has a focal length of 130 mm and here you can see it mounted in front of my M9:

 

sphericallens.jpg

 

The spherical and chromatic aberrations are considerable, but the light gathering capacity of this lens is fantastic.

 

Here you can see an image taken with this lens of my 8x10 inch Gandolfi next to an image taken with a Summilux 50/1.4 asph. from the same location but cropped to match the viewangle.

 

sphericallensimagecompared.jpg

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[quote=Lindolfi;2039

 

Here you can see an image taken with this lens of my 8x10 inch Gandolfi next to an image taken with a Summilux 50/1.4 asph. from the same location but cropped to match the viewangle.

 

sphericallensimagecompared.jpg

Given the image quality it produces, I'm not sure what the application of this lens would be.

 

Who makes this lens?

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I might be mistaken, but it seems to me that the lens shows a fair bit of spherical aberration. This is said to be the main source of bokeh, however, of which there is a fair deal.

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Yes Dan, that would be nice. The lens weighs 8 kilogram, so you also need a set of training sessions at the local fitness center.

 

Messucherkamera, the resolution is so bad that the lens can only be used for arty purposes. The lens was made about a century ago in China and its main purpose is to tell the future. Understandable that the image it produces is so vague!

 

MarkP: yes, lots of glow here.

 

Philip, I think you are right: even the in focus part has bokeh. :)

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I might be mistaken, but it seems to me that the lens shows a fair bit of spherical aberration. This is said to be the main source of bokeh, however, of which there is a fair deal.

 

I think the lens is a spherical aberration.

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The lens was made about a century ago in China and its main purpose is to tell the future.

Hmmm. I think that you ought to sell the Gandolfi before too much longer in that case;).

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I would like to see a tear down of the lens.

 

Well, by playing with the refractive index in a ray trace model I wrote, and obscuring parts of the entrance of the ball (central aperture or central obstruction) it appears that it is normal crown glass. The peripheral rays focus close to the surface, just outside the ball, while the central rays focus at about 25 mm outside the ball. Here the ray tracing for a point source at 10 meter distance of the ball. Tracing was done for three wavelengths (lambda=[687 589 486] nm) to show the chromatic aberration.

 

 

crystalballrays.png

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