Examples from the Web for orthochromatic
I will give to a common plate about four seconds, an orthochromatic plate under the same conditions five seconds.
This chart has been photographed in the orthochromatic and also in the ordinary way.
On the few occasions when orthochromatic plates are used the lamp need not be lighted.Photographs of Nebul and Clusters|James Edward Keeler
Orthochromatic results exhibited by Dixon and Sons at the photographic exhibition in October.The Evolution of Photography |John Werge
The isochromatic and orthochromatic plates on the market are corrected, and are the best to use.The Scrap Book, Volume 1, No. 1|Various