Silberra Pan 50

Silberra is a small Saint Petersburg outfit that cuts, perforates, and packages master rolls from Agfa-Gevaert surveillance stock. Pan 50 is one of two ISO 50 panchromatic films they sell. The other, Ultima 50, is the same emulsion on a thinner base. Same chemistry, same exposure index, different feel through the camera and on the development reel.

The Agfa parent stock was engineered for aerial reconnaissance, so resolution is the headline. Silberra publishes 290 line-pairs per millimeter at 1000:1 test contrast, which is in the same neighborhood as Adox CMS 20 II and well past anything in the Ilford or Kodak general-purpose lines. The trade-off in surveillance-derived emulsions is usually contrast, and Silberra has dialed it back during their finishing. Even so, this is not a forgiving film. Rated boxes range from 25 to 80, with their guidance noting that below 25 mushes contrast and above 80 pushes grain into noisier territory than a fifty-speed film should show.

The base is 0.1 mm clear polyester with anti-halation backing on the rear. Polyester stays flatter than triacetate in the negative carrier and is harder to tear if you grab the leader wrong, but it also pipes light down the edges in a bright loading room. Load indoors. Pan 50 takes filtration well: yellow at a 1.5x multiplier, orange at 1.8x, red at 2x to 3x.

Developer choice is wide open. Rodinal at 1:50 stays in the spirit of the Agfa origin and gives you a sharp, contrasty negative. PyrocatHD is the staining option for landscape workers who scan. D-76 makes the cleanest grain at the cost of some bite.

Sold in 35mm only, 36-exposure cassettes, direct from Silberra and through Freestyle in the US.

The reciprocity exponent is 1.33, on the steeper end for a modern emulsion. Zone Light Meter applies the correction past one second. A metered 30-second exposure becomes about 100 seconds at the negative, which adds up fast on slow-film tripod work. Plan accordingly when the meter pushes past a second at small apertures.