Kodak Ektachrome P800/1600

Ektachrome P800/1600 was the strange one in the Ektachrome line. The codename was EPH (later EPJ), the box read P1600 Professional, and Kodak's technical sheet listed it at base ISO 400 in normal E-6, with the expectation that you would push two stops in the first developer to land between EI 800 and 1600. A three-stop push to 3200 was also rated, though shadows started blocking and grain went coarse. The film basically did not have a box speed. You picked a speed by how you told the lab to develop it.

The design came from a specific working problem: 35mm photojournalism and concert work in the early 1990s when slide film was still required for editorial publication. Kodachrome 200 capped at ISO 200 and could not push. P800/1600 launched in 1992 alongside the 400X EPL release. It used T-Grain emulsion and held color stability surprisingly well when pushed two stops, with shadows shifting magenta only past EI 3200.

The EPH and EPJ codes in old datasheets refer to the same film through two updates. It came only in 35mm. No 120, no sheet. Production wound down with the rest of the Ektachrome line, and Kodak listed it as discontinued by April 2014. The reintroduced E100 from 2018 has nothing to do with this stock; if you want a fast slide for low light, push CineStill 800T past 1600 or shoot Fuji Provia 400X if you can find a freezer-stock roll.

What floats around now is twenty-plus years past expiration, and the response to that age is unkind for a film already designed to be pushed. Most expired-stock users meter at ISO 200 and accept whatever the lab brings back. Bracket aggressively.

Reciprocity exponent is 1.10. Zone Light Meter applies the correction past one second on the standard curve. A metered 30-second exposure climbs to about 35 seconds at the negative, which is rarely the math that matters: at ISO 800 or 1600 you are almost always at handheld shutter speeds, which is why this film existed in the first place.