Panchromatic means sensitive to all colours of light. Early orthochromatic film had very little sensitivity to red light, leaving red subjects as black in the resulting images. Panchromatic film - originally made by adding dyes to red-insensitive film, a result of work by Dr. Adolf Miethe, is capable of recording red subjects, as its sensitivity range reaches wavelengths of 660-730 nm (orange/red to red).
Panchromatic films had decreased sensitivity in the 490-540 nm area (blue to green), but were, however, still much too sensitive to blue light (what resulted e.g. in pictures with too bright sky and clouds invisible against white background), therefore required a yellow filter for correct representation of blue color brightness.
A typical panchromatic film is a bit too sensitive to red color (approx. 620 nm) as compared to yellow and green; a film with appropriately reduced sensitivity to red is called orthopanchromatc or rectepanchromatic.
As in the case of orthochromatic emulsion, isopanchromatic emulsion was sometimes distinguished from panchromatic emulsion. The difference was, similarly, in sensitivity to green - isopanchromatic emulsion had equal, correct sensitivity to green and yellow, while panchromatic emulsion had too low sensitivity to green as compared to yellow.
A variation of the panchromatic film was the so called superpanchromatic film (also called hochpanchromatisch, i.e. highpanchromatic in German), which had additionally increased sensitivity to red colors (in the 620-680 nm range) - as it was intended for use in artificial (tungsten) light of low color temperature. Superpanchromatic film had generally high speed (e.g. 400 ASA). Due to increased sensibility to long wavelenghts supenpanchromatic films had actually greater sensitivity under tungsten light than in daylight - for example Orwo NP 27 film of 27 DIN (400 ASA) could be exposed as 30 DIN (800 ASA) then.
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