Fujifilm Provia 400X

Provia 400X was the last fast slide film standing. By the time it was discontinued in 2013, there was no other ISO 400 reversal film in production from any major manufacturer. When it went, the category went with it.

Fujifilm positioned it as the photojournalism slide film. Press photographers who still shot film for wire transmission in the mid-2000s, and the magazine editorial market that still accepted or preferred transparencies, used it for indoor assignments, dimly lit events, and any situation where Provia 100F would have needed a push. At box speed it was slightly more saturated than 100F, with grain that was visible but controlled by slide-film standards.

Slide film at ISO 400 was always a compromise. The E-6 process does not push speed the way B&W chemistry can; every stop of pushed development on a slide film adds grain faster than the equivalent push on a negative emulsion. Provia 400X was more forgiving than earlier fast slide options, but it was still a film that asked for accurate metering. Underexpose a stop and the shadows fell apart; overexpose a half stop and the highlights clipped permanently.

The film came in 35mm and 120. The 120 version saw limited use; by the mid-2000s most medium-format work had shifted to digital or to color negative for the latitude advantage. The 35mm version stayed in circulation for editorial and photojournalism use until discontinuation.

Reciprocity exponent is 1.10. Zone Light Meter applies this automatically for exposures past one second, adjusting a one-second reading to about 1.1 seconds and a four-second reading to roughly 4.6 seconds. For a slide film, any long exposure was already a risk, so accurate reciprocity correction mattered more than with a forgiving negative stock.