Archived posting to the Leica Users Group, 2006/11/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 01:35 AM 11/14/2006, Stephen Gandy wrote: >But that is part of the reason the classic Heliar optical >design was so prized. The sharpest lens I have ever used, bar none, was the 3.5/7.5 Heliar on a Voigtl?nder Superb TLR. This was just one hell of a great lens. (I had my mother smuggle it into Canada where it was swapped for a Bullseye Contarex kit, a deal I still regret making.) Kingslake was underwhelmed by the Heliar but he tended to view this as a very early modified triplet intended for LF work and not as the capable lens it was later to become. The basic design dates from 1900 and was made by Hans Harting and in essence consists of a 2-1-2 design, with the middle element being a double concave lens. The evolved Heliar of the Interwar years was actually a modification orignally marketed as the Dynar: this design seems to have been the inspiration for both the fine Dallmeyer Pentac and for the Kodak lenses on the Medalist line. Tronnier and several of his pupils worked extensively on the Heliar design during the Interwar years, and it is these formulations which established the outstanding reputation for the design. Tronnier later used heavy-earth glasses to morph the basic Heliar design into the Apo-Lanthar lens, first with radioactive elements and later with non-radioactive lenses. Marc msmall@aya.yale.edu Cha robh b?s fir gun ghr?s fir!