Ilford HP5 (original)

Ilford launched the original HP5 at Photokina 1976 as the successor to HP4, with a worldwide rollout that started in 35mm-only batches sold first in Germany because that was Ilford's most profitable market at the time. The full 35mm, 120, and sheet rollout took another two years. The name HP stands for Hypersensitive Panchromatic, a designation Ilford had used since the original HP film in 1931. Five generations on, the speed sat at 400 ASA and the grain still ran traditional cubic silver.

The original HP5 ran for thirteen years before HP5 Plus replaced it in 1989. These are not the same film. HP5 Plus introduced finer grain, better push processing characteristics, and improved shadow detail under D-76 and ID-11. Photographers who shot both will tell you the original was grainier, slightly less linear in the mid-tones, and had a longer toe that handled press flash gracefully in a way the modern Plus emulsion does not match.

Compared to Kodak Tri-X of the same period, original HP5 had a softer highlight roll-off and slightly less aggressive grain in 35mm. ID-11 stock dilution was the canonical developer. Microphen pushed it to an honest 800 and a workable 1600. Fleet Street and Magnum shooters relied on it through the late seventies and early eighties.

Production ended in 1989 when HP5 Plus took over. Any rolls available now are at least thirty-five years old. The 120 in particular shows heavy base fog. Rodinal at high dilution gives a compensating effect that pulls some image back from under the fog level. Freezer-stored rolls fare better but should be treated as a special-occasion film.

Reciprocity exponent is 1.31, the conventional silver-grain baseline that matches Tri-X almost exactly. Zone Light Meter applies the correction past one second. A 30-second metered exposure becomes about 90 seconds at the negative. With aged stock bracket past that anyway. The base fog and decades of storage will eat exposure in ways no curve compensates for.