Rollei RPX 100

RPX 100 sits in a crowded slot. Kentmere 100, Fomapan 100, Adox CMS (for the masochists), Ilford FP4+: every budget and mid-tier position already has an occupant. What RPX 100 offers is cleaner grain than Foma at a price that undercuts Ilford and Kodak, with a consistent supply chain through Maco that European shooters have found reliable.

The emulsion is coated for Maco by Harman Technology in the UK, the same Ilford-owned plant that makes Kentmere. In 35mm RPX 100 tracks closely enough with Kentmere 100 and the current AgfaPhoto APX 100 repackage that most users treat them as siblings. Grain is fine and somewhat tight; nothing architectural or tabular here, just well-behaved cubic crystals that print and scan without drama. Tonal response is fairly linear through the mid-tones, which makes it useful for portrait work where you want accurate skin rendering without the heavy compression some older emulsions apply to zones VI and VII.

It comes in 35mm, 120, and sheet sizes, which is useful for shooters who want to run the same emulsion across formats. Comparing a 35mm negative to a 4x5 negative from the same scene is a legitimate technical exercise, and RPX 100 is consistent enough across formats that the comparison is meaningful.

Processing is straightforward. D-76 1:1, Rodinal 1:50, or HC-110 dilution B all produce sensible results. There is no quirky development behavior to manage.

The reciprocity exponent is 1.31, matching the rest of the RPX family. Zone Light Meter corrects automatically past one second, which comes up more often with ISO 100 film than people expect: interior available-light situations, dawn and dusk work with a tripod, and any time you are using strong filtration.

FP4+ has the lineage and the broader community knowledge base. RPX 100 has the price. Which matters more depends on your workflow.