Fomapan R 100

Fomapan R 100 is one of the few black-and-white reversal films still being manufactured. You shoot it, it processes to a direct positive, and you get a slide: clear film base with a silver positive image that you can project, contact-print, or scan as a positive file without inversion. The process is multi-step black-and-white reversal chemistry, not C-41 or E-6. A first developer is followed by a bleach, a clearing bath, a re-exposure (or a chemical reversal bath), a second development, and a fixer, which is why most labs no longer run it. In practice that means processing it yourself or finding a specialist lab.

The image quality is what you'd expect from a 100-speed panchromatic emulsion processed to a positive: fine grain, good sharpness, contrast that is inherently higher than a corresponding negative because the reversal process compresses the tonal range at both ends. This is not a film for high-contrast situations unless you want something close to graphic. In soft even light it produces beautiful, luminous results.

The usable exposure latitude is narrow compared to a negative film. One stop of overexposure produces a noticeably thin slide; one stop of underexposure produces a dense one with blocked shadows. Metering accurately matters more here than with any Fomapan negative stock. The film can be processed to a slightly softer positive by adjusting bleach time, but the margin is small.

Available in 35mm for still cameras, and also in 16mm, Double 8, and Double Super 8 for cine work. No 120 version exists at time of writing.

Reciprocity exponent is 1.31. For any long exposures past one second, Zone Light Meter folds in the correction automatically. This is especially relevant for still-life or architectural work done on a tripod where the narrow latitude of reversal processing makes accurate exposure time doubly important.