Suter Rapid Aplanat

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  jstraw

• Dec 16, 2006

Love it. Is it the Petzval again?

 

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  jstraw

• Dec 16, 2006

Oh! Guess not...hmmm...similar circular thing going on though.

 

• ineffablething

• Dec 16, 2006

I don't know if it's a petzval or not. It sure looks like one.

 

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  smieglitz

• Dec 16, 2006

I'm surprised by this image. Weren't Aplanats (Rapid Rectilinears) corrected so not to do this swirl effect? I thought the elimination of the "roundness"/field curvature common to the Petzval design was the point of the Aplanat/RR design, at the cost of reduced maximum aperture (IIRC). Can you estimate the focal length and maximum aperture for this lens?

 

• ineffablething

• Dec 16, 2006

I measured it at f6 and 275mm.

 

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  Ole

• Dec 17, 2006

A Suter Rapid Aplanat No. 2 is an f:5 270mm lens, intended to cover 13x18cm (5x7").

When used on a far bigger film than the intended coverage, practically any lens will give "swirlies" unless it's physically vignetted.