Heliar
Voigtländer Braunschweig Heliar 1:4.5 f=13.5cm on Voigtländer Bergheil image by Petru Schiopu (Image rights) |
The Heliar is a lens designed and made by Voigtländer. It was developed in 1900 by Dr. Hans Harting, and patented in Germany (1901), Britain (1901) and the USA (1902).[1] It comprises five glass elements: the front group is a cemented doublet of positive power, composed of a crown glass element at the front, cemented to a flint glass; there is a central, diverging element of a different crown glass, and the rear group is another cemented doublet, identical to the front group.[2] Thus the Tessar of Zeiss seems to be a simplified Heliar, without the front group divided, being less flexible concerning corrections. However, the Heliar clearly predates the Tessar by about a year. Kodak patented one of its Ektar lenses with an almost similar but not identical concept. Dallmeyer's Pentac was almost alike the Heliar, but a little faster. Voigtländer itself created variations of the Heliar. The position of the two cemented converging lens elements could be outer or inner elements of the lens. The latter concept was introduced in 1902.
Voigtländer Braunschweig Heliar 1:4.5/24cm image by phollectormo (Image rights) |
Voigtländer used the lens in the way Zeiss used the Tessar; it was the lens fitted to most of the company's high-specification cameras for many years. Large format versions like the Universal-Heliar 1:4,5 F=30cm were available.
The original Heliar design was an f/4.5 lens; f/3.5 versions of the same optical design were offered fairly soon after (alongside the f/4.5). The wider-aperture lens has a slightly narrower field of view.[3]).
Voigtländer&Sohn Heliar 1:4.5, original 5-element concept scanned by Dirk HR Spennemann (Image rights) |
Voigtländer Braunschweig Heliar 1:4.5 F=12cm image by ebayer www_leicashop_com (Image rights) |
f3.5 Color-Heliar for Voigtländer Bessa medium format folders image by Paulo Moreira (Image rights) |
Modern Heliar and APO-Lanthar
Apo-Lanthar 1:4.5 f=150mm large format lens image by Gerard Vogels (Image rights) |
In 1950 the team of Dr. A.W. Tronnier refined the Heliar design to the Color-Heliar for medium format cameras, based on the original lens design, whilst at the same time the large format Heliars had the 1902 design. A true redesign by Tronnier with the new Lanthan glass had better lens fault corrections, but was explicitely not marketed as Heliar but as APO-Lanthar since the Heliar's remaining lens faults were seen as the lense's characteristics! Another good reason was that the new lens was the world's first apochromatic lens, meaning color-corrected for 3 instead of 2 spectral colors.
Super Wide Heliar on Leica III image by Romuald Swieconek (Image rights) |
Later Voigtländer or its successor Cosina managed to develop new Heliar lenses for 35mm format which are much faster or have a much wider angle of view, in a wide range from ultra wide angle to portrait telephoto. Therefore new lens designs with 6, 8 or 10 elements were derived from the old Heliar concept. The old Heliar concept was only revived for the standard lens focal length 50mm, but very successfully concerning the resulting quality. Nikon and Pentax also built fine standard lenses after the Heliar concept for a while.
focal length | aperture | elements | groups | iris blades | angle of view | |
---|---|---|---|---|---|---|
Ultra Wide Heliar | 12mm | f5.6 to f22 | 10 | 8 | 9 | 121° |
Super Wide Heliar | 15mm | f4.5 to f22 | 8 | 6 | 10 | 110° |
Heliar | 50mm | f3.5 to f22 | 5 | 3 | 10 | 46° |
Heliar | 50mm | f2.0 to f22 | 5 | 3 | 11 | 46° |
Heliar | 75mm | f1.8 to f16 | 6 | 3 | 10 | 33° |
Color-Heliar | 75mm | f2.5 to f16 | 6 | 5 | 10 | 32° |
APO-Lanthar | 90mm | f3.5 to f22 | 6 | 5 | 10 | 27° |
APO-Lanthar | 90mm | f3.5 to f22 | 7 | 5 | 9 | 27° |
Color-Heliar | 125mm | f2.5 to f22 | 11 | 9 | 9 | 32° |
APO-Lanthar | 180mm | f4.0 to f22 | 9 | 7 | 9 | 14° |
Bessa-T w/ Apo-Lanthar 90mm F3.5 image by Carlos Santisteban (Image rights) |
Notes
- ↑ Greenleaf, Allen R. (1950), Photographic Optics. Macmillan, New York. pp80 & 83.
- ↑ US Patent 716035 of 1902, in the name of Carl Harting, for Voigtländer, at Google.
- ↑ A Voigtländer catalogue of 1927, at Camera Eccentric shows both the f/4.5 and f/3.5 lenses. The angle of view of the f/3.5 lens is given as about 50°; that of the f/4.5 is given as about 58° (up to focal length of 24 cm; for some reason (perhaps simply bellows extension) it is given as 45° beyond that.