Celor lens
{{Infobox lens design
| name =Celor
| scheme =Celor lens (Wix).svg
| year =1898
| author =Emil von Hoegh
| elements =4
| groups =4
| aperture ={{f/|4.5}} and 6.3
}}
A Celor lens (also known as a symmetric dialyte){{cite book | last=Geary | first=Joseph | title=Introduction to lens design with practical ZEMAX examples | publisher=Willmann-Bell | publication-place=Richmond, Va | year=2002 | isbn=978-0-943396-75-0 | chapter=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 (1892) designed for the German company Goerz.{{cite book | last=Born | first=Max | title=Principles of optics: electromagnetic theory of propagation, interference and diffraction of light| publisher=Cambridge University Press | publication-place=Cambridge New York | year=1999 | isbn=978-0-521-64222-4 | page=[https://archive.org/details/principlesoptics00born_986/page/n300 265]}} It was originally named the Double Anastigmat Goerz [Dagor] Type B, sold in both {{f/|4.5}} and {{f/|6.3}} versions; in 1904, the faster {{f/|4.5}} version was renamed to the Celor and the {{f/|6.3}} version was renamed to the Syntor.{{Cite book |last=Kingslake |first=Rudolf |title= A history of the photographic lens |publisher=Academic Press |year=1989 |isbn=0124086403 |edition=1st, hardback |location=San Diego |pages=81–102 |url=https://archive.org/details/historyofphotogr0000king/ |chapter-url=https://archive.org/details/historyofphotogr0000king/page/100/mode/2up |url-access=registration |chapter=6: The First Anastigmats}}{{rp|100}}
Similar four-element air-spaced symmetric dialyte lenses were released by Steinheil (Unofocal, 1901), Kodak, and Taylor, Taylor & Hobson (Aviar, 1917).{{rp|100–101}}