The Omag tri-color filter attachment for Contax cameras facilitates the taking of color separation photographs on 35mm film. Photographs are taken on successive frames through red, green and blue filters. The Omag tri-color filter holder's 42mm opening fits the 50mm f/1.5 Sonnar lens. The attachment is a slip fit over the lens barrel and it's clamped on by turning a small screw. The filter holder can also be used on other lenses that have similar lens barrel diameters.
The filters can be rotated 360 degrees. There are click stops that serve to locate each of the filters directly in line with the lens. By rotating the filter carrier down, as in the photo above, the viewfinder is unobstructed. After aiming and focusing is completed, the carrier can be rotated up so that either the red or blue filter is in position, ready for the first exposure.
The Omag tri-color blue filter is in position.
The Omag tri-color green filter is in position.
The Omag tri-color red filter is in position.
When the filters are in front of the lens there is some view and rangefinder obstruction. Of course, there is no need to refocus between shots. The camera will be mounted on a tripod and focusing is done before positioning the filters. If however, it is desirable to check the subject through the viewfinder between shots, a solution is to attach an accessory viewfinder such as the Zeiss 440 universal finder seen in the photographs.
The box lid is embossed: "OMAG" Contax Tricolorfilters. The lettering is faint but legible.
Omag was a Swiss manufacturer of optical products and camera accessories. Omag products included high quality camera filters, accessory rangefinders, lens hoods, photographic enlargers and microscopes. Optik und Mechanik A.G. was formed in Switzerland in 1925. The company name was changed to Omag Optik und Mechanik A.G. in 1931, Omag being an acronym of the former company name. The names "Omag" and "Omag Switzerland" were both used in the marketing of their products.
In the USA, another firm made and sold camera filters under the Omag name but it was not selling Omag Switzerland products. The companies were involved in a trademark dispute: Omag Optik Und Mechanik A. G. v. Weinstein.
I have not been able to find information on the Omag Contax tri-color filters in my Zeiss collector books, nor on the Web. It may be that few were sold. My hunch is that it dates to the early to mid-1930s. With the introduction of Kodachrome for still cameras and Agfacolor Neu in 1936 as well as Kodacolor in 1942, the need for color separations in an amateur format would have passed.
During the 1930s, Leitz New York marketed an OMAG sliding tri-color filter holder for Leica cameras. Scan down the linked page to find a description and photograph of the OMAG.Related Information
Page created August 22, 2022