Film Washi "F" 120

Overview

"F" is a fluorographic X-ray film — the stock used for mass lung screening — coated by machine in another factory and hand-spooled onto 120 by Film Washi in Brittany. It carries a single emulsion on one side of a 100 µm polyester base rather than the double coating of dental and medical sheet film, so no special handling regime is needed: it develops as an ordinary black and white negative in ordinary chemistry. Film Washi publishes 9 min in Rodinal 1+25, 8 min in Ilfotec LC29 1+19, 11 min in D-76 1+1 and 4.5 min in HC-110 dilution A at 20 °C, and says to use Ilford FP4 times and dilutions for any developer not on that list. It is orthochromatic with a maximum sensitivity of 575 nm, so reds record dark and you may work under a red safelight. There is no anti-halation layer and highlights bloom back through the base as a halo; the datasheet rates the grain high and the contrast medium, and states that this diffusion is noticeably gentler in 120 than in 135 and varies with the angle of the light. Unlike the 135, a 120 roll can be loaded as usual — the blank-frame routine is a 135 precaution — but Film Washi advises securing the roll with a rubber band or tape as you unload it. The rolls are hand-spooled, and Film Washi warns that a few very delicate cameras can have trouble handling them: never force the winding lever.