I cannot find the descriptions of Voigtlander lens anywhere. What I would like to find out is the actual differences between their models, what those names mean?
I believe these names are assigned to specific optical constructions.
I know more or less the difference in their aperture ranges and I keep thinking this is the reason for those, but there must be a proper explanation of those, right?
phinix wrote:
I cannot find the descriptions of Voigtlander lens anywhere. What I would like to find out is the actual differences between their models, what those names mean?
I believe these names are assigned to specific optical constructions.
I know more or less the difference in their aperture ranges and I keep thinking this is the reason for those, but there must be a proper explanation of those, right?
Like leica the names have evolved to relate primarily to the fastest aperture of a lens, not the optical formulas. But this is inconsistent where Leica names are very consistent.
IIRC the original APO-Lanthars were Heliars that had a lanthanide glass element that allowed for apochromatic correction. Those lenses still command high prices these days. BITD (as in about a century and a quarter) Heliar meant 5 elements in 3 groups and allowed for better coverage than Tessar designs (in LF, coverage is important). I don't think it has much in common with the modern designation of Heliar.
I see that Cosina have Voigtlander Classic and Vintage lines, not to be confused with vintage or classic Voigtlanders. So the 150mm APO Lanthar is a Voigtlander classic and a classic Voigtlander, but not a Voigtlander Classic. I know English word ordering is important (house cat vs cathouse) but that's a bit much!
The nomenclature is based on lens formula, i.e. the design recipe, for the most part, although there can be variations within each line. Nocton is used for large aperture lenses irrespective of a specific formula, similar to Leica's use of the term summilux. Otherwise, from various sources...
"The original "Ultron" was a 50mm f/2.0 lens with 6 elements in 5 groups designed for the Voigtlander Prominent camera and introduced ca 1950. It was designed by A.W. Tronnier as an improvement on his own Schneider-Kreuznach Xenon (c.a. 1937)"
"Skopar, Color-Skopar = tessar, (four elements in three groups)"
"The Heliar was developed in 1900 by Dr. Hans Harting, and patented in Germany (1901), Britain (1901) and the USA (1902), originally as a symmetrical 5-element variant of the simple anastigmatic and well color-corrected Cooke triplet."
The answer to this question is not easy as it seems Voigtlander has diverse reasons for naming their lenses. We know that Leica names their lenses based on the widest aperture (Noctilux, Summilux, Summicron, Elmarit, Elmar, etc.). We know that Zeiss used to name their lenses based on lens design (Biogon, Distagon, Planar, Sonnar, etc.) and now names lenses based on bird names (Otus, Milvus, Loxia, etc.) which clearly also convey a level of prestige.
Voigtlander has always taken a more varied approach with Nokton reserved for fast lenses (generally at least as fast as f/1.5) and some names based on lens design (e.g., Heliar) and some names at this point clearly based on prestige (e.g., APO Lanthar lenses are their highest quality lenses). Although some names were clearly based on lens design originally I think you can take modern Voigtlander naming to mean the following which is a mix of lens speed, design, and prestige:
Nokton: A fast lens typically f/1.5 or faster
Ultron: A fairly fast lens typically f/1.7 to f/2.0
Skopar/Color Skopar: A slower lens typically slower than f/2.0 including some with an APO designation
Heliar: A more classic lens design that points toward the classic Heliar design and includes everything from f/1.5 to f/3.5 lenses
APO Lanthar: The most highly corrected lenses and is a prestige label that has little to do with the lens design itself
So Voigtlander lenses in recent times seem to be a mixed bag in how they are labelled, but I don't think they were ever labelled in a consistent way like Leica and Zeiss lenses.