Anscochrome 50

Anscochrome was Ansco's answer to Kodachrome, made in Binghamton, New York from 1955 onward. The 50-speed version arrived in 1963. The chemistry is fundamentally Agfa's: a subtractive integral tripack reversal film with color couplers built into the emulsion layers, descended from Agfacolor Neu (1936). Unlike Kodachrome, which required Kodak's proprietary lab processing, Anscochrome could be reversal-developed by independent labs and by enterprising amateurs using Ansco's published chemistry, which became the entire pitch of mid-century Ansco advertising.

The home-processing angle pulled in a small but committed base of hobbyist slide shooters and 16mm motion picture amateurs. The 50-speed variant was sold specifically for 16mm work; Ansco made other speeds in 35mm for stills. By the standards of the day ISO 50 was respectable for a slide film, sitting a stop faster than Kodachrome II at ASA 25.

Where Anscochrome lost out was longevity. The dye couplers built into the emulsion were less stable than Kodachrome's, and fifty years later surviving slides have often faded badly. Cyan and magenta layers shift, the emulsion can develop a spider-web crazing as it pulls from the base, and shadows go murky. Next to a well-stored Kodachrome of the same year, a surviving Anscochrome 50 looks like a different medium. When fresh, color ran warmer and less saturated than Kodachrome, with believable skin tones.

GAF, which had absorbed Ansco by the 1960s, killed the consumer photo line in 1977. Anscochrome 50 specifically went out of production in 1968. Commercial E4 chemistry stopped being available decades ago.

Format was 16mm motion picture only for the 50-speed variant. The 35mm slide product line ran different speeds.

Reciprocity exponent is 1.10. Zone Light Meter applies the correction past one second. A metered 5-second exposure becomes about 6 seconds at the negative, which is academic now. If you find an unexposed roll, the question is not how to meter it but whether anyone can still process it.