Technical Pan

Technical Pan was a black and white film produced by Kodak. It was generally used as a very slow film, rated at ISO 25 or even 16, although it could be rated at up to ISO 320. It was discontinued in 2004

Tech Pan, as it is often known, was very popular among astronomers. It was capable of recording extremely fine detail, and its sensitivity curve extended much further into the red than that of most films. In particular, it was very senstitive to light emitted by hydrogen at 656.3nm, which made it very useful for a wide range of astronomical imaging.