This is a lens design created simultaneously by two lens makers: Dallmeyer and Steinheil back in 1866. Its big virtue is rendering straight in the image the straight lines in the scene. Very important in architecture and urban scenes in general. Lenses able to do that before had very low aperture and demanded very long exposures. Very convenient then to call this type Rapid Rectilinear, because it was a solution for both desirable qualities.



It consists of two doublets symmetrically arranged around the iris. The tricky part, besides the geometry in itself, is the choice of glasses to form the doublets.

It was very successful and many manufacturers launched their own Rapid Rectilinear or Aplanat lens. For more than 60 years it remained the first choice as a generalist lens. There were some yielding wide angle and others with higher aperture intended for portraiture. The next step-change in lens construction was the anastigmat but that came later at the turn of the XX century.



This one, the Lynkeioskop, was one of the first models launched by a house that would make history in the photographic industry: Goerz, from Berlin. That was in 1886 and it was designed by C.Moser. It is considered one of the best Rapid Rectilinears or RR and first of a series of landmark lenses by Goerz, like the Dagor or Hypergon.

The larger aperture, 4 does not correspond to the system we are used to: 4 - 5.6 - 8 - 11 - 16 - 22 etc. It is equivalent to f 1:6.3. Below you have a table for conversion. That was published in the first issue of Photominiature in April 1899.



Most of the above information I researched on "A history of the photographic lens" by Rudolf Kingslake, Academic Press Inc. ISBN 0-12-408640-3. It is an excellent source for understanding the genealogy of most of the lenses ever produced and the problems associated to lens construction.
If you want something online: download the "A Lens Collector Vade Mecum" it is only 15,99 USD and an invaluable source of information. Go to: Lens Vade Mecum It has more than 700 pages with thousands of lenses description, pictures and diagrams.



Here it is fitted to a Graflex Auto RB. This is a single lens reflex camera in 9x12 cm format. really convenient for portraiture.