Rollei RPX 25 is a 135 black and white film, 36 exposures, rated ISO 25. The emulsion is coated on a polyester (PET) base and, per the maker’s own description, is built on Agfa-Gevaert aerial film technology — the same lineage as Agfa Aviphot Pan 80.
How the picture looks
The maker states high resolution and very fine grain. Exposed at EI 25 the characteristic curve keeps a distinct S shape: the result is contrasty, with little shadow detail and clearly separated mid-tones. If that much contrast is not wanted, the maker advises giving more light and shortening development to match.
The infrared effect
Sensitisation is superpanchromatic, so infrared work is possible — but only with a filter that blocks visible light up to about 715 nm (the maker names the Heliopan RG 715). Without such a filter there is no IR effect at all.
What to shoot on it
A tripod, bright light, and subjects where the resolution ceiling matters: landscape destined for a large print, architecture, still life. ISO 25 is very little, so handheld interiors are out.
About the base
The PET base carries a special coating that improves film transport in the camera. It is also clearer than acetate: load and unload in subdued light to avoid light piping along the edges.
Processing and scanning
Ordinary black and white processing. Take the times from the maker’s table for your developer — with this much inherent contrast, development time matters more here than usual.
