Kodak Aerographic 2402

Plus-X Aerographic 2402 is a Kodak panchromatic aerial film that was never built for pictorial work, and using it that way means accepting a different set of rules. The spec sheet headline is ISO-A 200, but the A stands for aerial. Kodak set that figure assuming development to roughly gamma 1.80, far more contrast than pictorial work wants. Pull contrast back to a print-friendly index and the effective speed collapses. Most ground users land between EI 50 and EI 64 with D-76 or HC-110 at conventional times.

The emulsion has extended red sensitivity, engineered to punch through atmospheric haze on high-altitude reconnaissance. On the ground it gives skies a Tri-X-Pan-like rendering with a hint of red filter already built in. Grain is medium, resolution high (Kodak quoted around 80 to 125 line-pairs per millimeter depending on contrast), and the base is 4-mil ESTAR rather than acetate. ESTAR is dimensionally stable and tear-resistant. It also chews ordinary slitting blades.

Who buys this. Large-format shooters cutting 70mm or 9.5-inch bulk down to 4x5 sheets, because per-sheet cost on surplus channels is a fraction of fresh Kodak or Ilford. Photrio threads on 2402 stretch back fifteen years and most users settle on the same recipe: rate at 50, HC-110 dilution B for around six minutes at 68F, print on grade 2 or 2.5.

Discontinued for new production though Kodak listed it in the aerial catalog into the 2010s. What circulates now is surplus, often forty years old. Cold storage holds it well. Warm storage produces base fog no developer trick recovers.

Formats were 70mm x 150ft rolls and 5-inch and 9.5-inch wide rolls. No retail 35mm or 120 ever. You cut it yourself in the dark.

Reciprocity exponent is 1.31, the conventional silver-grain baseline. Zone Light Meter applies the correction past one second. A metered 30-second exposure becomes about 90 seconds at the negative. For sheet-film tripod work at small apertures, that threshold comes up almost immediately.