Purely coincidentally, Planar optical scheme was invented by Zeiss. So, like it or not, most if not all 50/1.4 lenses have some Zeiss Inside (tm).
On 24 Jan 2017 13:17, "Ralf R Radermacher" <fotor...@gmx.de> wrote: Am 24.01.17 um 11:34 schrieb Steve Cottrell: What's the difference between a Planar and a Tessar? > The Tessar is a four-element lens with a maximum aperture of 2.8, the Planar has six or seven elements and opens up to 1.4. The Tessar had its hayday when a lack of efficient lens coatings acted in favour of designs with less glass/air surfaces. The Planar has a far better sharpness distribution. https://en.wikipedia.org/wiki/Tessar https://en.wikipedia.org/wiki/Zeiss_Planar Ralf -- Ralf R. Radermacher - Köln/Cologne, Germany Blog : http://the-real-fotoralf.blogspot.com Audio : http://aporee.org/maps/projects/fotoralf Web : http://www.fotoralf.de -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
