Celor lens

A Celor lens is a highly corrected lens of the Dialyt type, designed for process photography, involving reproduction at or near 1:1 scale.

Design

It was developed in 1898 by Emil von Hoegh, as a development of his earlier Dagor lens designed for the German company Goerz. It was originally named the Double Anastigmat Goerz Type B, sold in both and versions; in 1904, the faster version was renamed to the Celor and the version was renamed to the Syntor.
Similar four-element air-spaced symmetric dialyte lenses were released by Steinheil, Kodak, and Taylor, Taylor & Hobson.