Since both Wisner and Lotus View make 20 x 24 cameras, there must be lenses that cover this format. This means an image circle of diameter at least 800mm, preferably 900mm to allow for movements. Does anyone know what's available? In particular, what is the choice of focal lengths?

-- Stewart Ethier (ethier@math.utah.edu), June 02, 1998

Answers

The Lens and Repro Equipment Corp. has advertised a 150 mm Goerz Hypergon that covers 20 x 24". I believe ther are also many long focal length process lenses that would cover this size.

-- Sean Donnelly (donnelly@c-com.net), June 03, 1998.

I can now answer my own question to some extent, in case anyone's interested. I just found in my basement a 1969 Burke & James catalog, with something like 40 pages devoted to lenses. First, there are 7 Goerz Red Dot Artar lenses that cover 20 x 24, with focal lengths of 19, 24, 30, 35, 42, 47.5, and 70 inches. The first two are available in Acme M-X synchro shutters, while the last 5 are available only in barrel. The coverages of the 7 lenses are respectively 20 x 24, 24 x 32, 30 x 40, 36 x 45, 48 x 56, 48 x 64, and 72 x 90 inches. Actually, the catalog says "covers at same size", but I'm not sure exactly what this means. Does it mean at 1:1? Are these lenses intended for close-up work?

The catalog contains 7 pages of anastigmat lenses, but only two cover 20 x 24: both Goerz Dagor Series III f/7.7 in barrel. The 24 inch version covers 18 x 36, while the 30 inch version covers 30 x 40.

Finally, there are two pages of process and copy lenses, and I counted 24 of them that cover 20 x 24 or more. Manufacturers include Goerz, Rodenstock, Carl Zeiss, Boyer, Metra, Taylor Cooke, Ross, and Wray.

Presumably, most of these lenses are available on the used market. The prices in the catalog seem very low---I guess there's been some inflation in the past 30 years!

-- Stewart Ethier (ethier@math.utah.edu), September 01, 1998.

Wisner has a 20 X 24 Lens Guide (posted 4/30/99) listing "classic" lenses with a promise to add 'certain recent production lenses to this table in the near future.' http://wisner.com/20x24lens.htm

-- Boyd Hecker (cdbluez@aol.com), January 26, 2000.

Artars are process lenses, intended for 1:1 or so, which is most likely what that coverage spec refers to.

-- John Hicks (jbh@magicnet.net), January 27, 2000.

Stewart, "covers at same size" DOES mean 1:1, You would need an Artar of 30" or more to cover 20x24 at infinity. Dagors from 16.5"(no movement) and up will do nicely. Zeiss wide angle Protars in longer focal lengths(rare) are great. Fujinon 600 C is my main lens for infinity to 1.5:1. Tracy Storer www.mammothcamera

-- Tracy Storer (tstorer480@yahoo.com), December 15, 2001.