Rodenstock eurygon lens

Anton Lukoszevieze

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Anyone know anything/ever use a Rodenstock Eurygon 300mm lens, f4.5 so quite fast?

I read in my lens vade.
Eurygon f4.5 300, 360, 420mm This was a plastic graduation portrait lens, using a triplet
design. H&D gives 210-600mm, and confirms it is a triplet. Frerk confirms it is a triplet, and mentions small
sizes for movie and macro work, possibly the f3.5 version, and large ones for general use. Coverage increases
from 48° to 60° or to 70° as it is stopped down. It is suggested to use 21cm for 13x18cm.
 

Ole

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All I know about it is that it's a triplet, has a large max aperture, and is mentioned as a "Porträtanastigmat" and "Weichzeichner" - so it's a soft-focus portrait lens.
 

Piotr Hernik

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Hello,
Has anyone know if 300mm Rodenstock Eurygon shall cover 8x10 format? I wonder how does this lens perform and if it can be compared in rendition to other (portrait?) lenses.
Thanks in advance for all info.
Best,
 

Ole

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At portrait distances, I'm sure it will cover. Thiele quotes a 45 degree image angle, meaning it won't cover at infinity - for a given definition of coverage.
 

Piotr Hernik

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Thank you, Ole
Could you please explain what is the difference between image circle and image angle in respect to lens coverage? This is unclear for me.
 

Ole

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Image angle is the angle of the "cone of sharpness", and as such it depends ONLY on the lens construction and not on the focal length.

At infinity, the distance from the lens nodal point to the film plane is equal to the focal length, so the radius of coverage is given by tan(phi/2)=r/F, so a 300mm lens with 45 degrees image circle covers r=tan(22.5)*300 or about 124mm radius, 248mm diameter of coverage.

As you focus closer the distance from lens node to film plane increases, so that the diameter of coverage increases. But the angle remains the same.
 
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