msbarnes
Well-known
I don't know too much about optics but the xenar performs like a tessar and the xenotar performs likes a planar. People usually treat them as equals, so my question is: do these lenses share the same exact design? There are probably other instances but this spring up to mind because I'm looking for a Rollei (and I don't care who makes the lens, personally).
I was a bit confused because I thought that Leica and Zeiss didn't share the same designs because of patent laws (e.g. summarit a response to the sonnar), but if this is the case, then why is it that Schneider and Zeiss have shared the same designs (assuming that they do)?
I was a bit confused because I thought that Leica and Zeiss didn't share the same designs because of patent laws (e.g. summarit a response to the sonnar), but if this is the case, then why is it that Schneider and Zeiss have shared the same designs (assuming that they do)?
Roger Hicks
Veteran
Same? No. Similar? Often.
Cheers,
R.
Cheers,
R.
BobYIL
Well-known
The Xenar is a Tessar design (Leica Elmar too) comprised of four elements in three groups.
The Xenotar is a modified double-Gauss design with 5 elements in four groups (always, as far as I know..)
The Planar is again a double-Gauss one, from 5 to 6 elements for Rolleiflex models or 6 to 7 elements for Hasselblad Planars. Below is different Planar designs employed with Rolleiflex models however, as you see, they are not the same as the Xenotar design.
6-element Planar. (With small modifications ZM Planar as well.)
For more information about several Rolleiflex models, refer to:
http://www.rolleigraphy.org/rolleiflex_compare.html