Kodak Verichrome (pre-Pan)

Original Verichrome is the orthochromatic film Kodak made for box cameras. It ran from 1931 to 1956, when Verichrome Pan replaced it. The emulsion was built for forgiving exposure in cameras with no controls: most Brownies and folders had a fixed shutter near 1/30 and one aperture, so the film had to handle a five-stop swing. Verichrome handled it because Kodak coated two emulsions on the same base, one slow and one fast, working together to extend the usable range.

Orthochromatic means insensitive to red light. Skies render bald white because blue dominates and reds fall into shadow. A red sweater photographs almost black. That look is unmistakable in family snapshots from the thirties and forties. It is the visual signature most people associate with pre-war photography even when they cannot name why. Panchromatic Verichrome Pan in 1956 fixed the sky problem but lost the tonal character of the older stock.

Box speed is roughly ISO 50 in daylight, though Kodak rated it on Weston and ASA systems that do not map cleanly to modern numbers. Under tungsten the effective speed drops to around 20 because the red-heavy lamp light is largely invisible. Outdoor at f/11 and 1/50 was the working assumption.

The double-coat construction held detail in scenes with deep shadow and bright sky where any single-coat film would have clipped. That latitude is the only reason snapshots from the era exposed correctly as often as they did. Compared with the Pan that followed, the original was slower, simpler, and friendlier to mistakes.

Formats were 116, 120, 616, and 620 rolls, tied to Kodak's consumer ecosystem. None of those mounts survive in production, and any surviving roll is at least seventy years past expiration.

The reciprocity exponent is 1.31. Zone Light Meter applies the correction past one second. A metered 30-second exposure becomes about 90 seconds at the negative. For a film built around handheld daylight box work, that math rarely came up. For anyone shooting a surviving roll today on a tripod, it matters.