Agfa Isopan ISS

Isopan ISS was the press and general-purpose film in the long-running Agfa B&W range, introduced in 1935 as a Superpan replacement and still the default load for most working photographers in West Germany through the postwar decades. Late 1950s data sheets rate it at 21 DIN, which converts to ASA 100, on a triacetate base for 35mm and a thicker acetate for medium-format roll. The ISS suffix stood for Iso Super Sensitive, marketing language that placed it above the slower Isopan F and FF films in a tier competing with Kodak Plus-X and Ilford FP3 in the European market.

The rendering is what people remember. The midtones land smoothly without the slight steepness of FP3, and the highlights compress gracefully rather than peaking sharply. Press shooters preferred it for newspaper work because the latitude tolerated rough metering on street and event coverage. The grain is cubic, structured, visible but not coarse, comparable to Plus-X of the same period and slightly tighter than Adox KB-21 in the same speed class.

Development in Atomal F was the Agfa recommendation, giving the cleanest midtone scale and the tightest grain. Rodinal 1:50 produces a sharper print with more visible grain structure, which was the West German press-shooter preference for hand enlargements. ID-11 and D-76 both work with no surprises. Pushing to ASA 200 with extended development holds up; ASA 400 starts blocking shadows.

Production continued under the Agfa-Gevaert merger from 1964 onward but tapered off through the 1970s and wrapped around 1980 as the company shifted focus to color and to the later Agfapan APX line. Sealed rolls turn up regularly in estate sales across Europe, mostly 35mm and 120, with the occasional sheet-film size. Freezer storage preserves the speed and the curve. Warm-stored rolls coated in the late 1970s fog noticeably; anything past the 1980 production wind-down is suspect unless it has lived in a freezer.

Reciprocity exponent is 1.31. Zone Light Meter applies the correction past one second. A metered 30-second exposure becomes about 90 seconds at the negative. Available-light press shooters knew the rule of thumb without doing the math; the app folds the correction in automatically the moment you cross the one-second mark.