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Development time

Rollei/Maco RPX 400 in Microphen

7:00 at 20°C (68°F), stock dilution, box speed.

Start timer · 7:00
Time
7:00
Standard
Dilution
Stock
Temperature
20°C
68°F
Box speed
ISO 400
B&W

All 4 times

DilutionEITimeTempAgitationEvidenceTimer
Stock4007:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
Stock800+1 stop10:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+140013:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+1800+1 stop16:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer

EI is the speed the film was rated at when shooting. Evidence says where each time comes from: the manufacturer’s own data, a named test, a compilation or several agreeing reports (community consensus), or one person’s report. Times marked “not yet verified” come from secondary sources and haven’t been checked against a manufacturer datasheet. Where sources give different times, every one is listed and marked “sources differ”.

Other temperatures

18°C64°F19°C66°F20°C68°F21°C70°F22°C72°F23°C73°F24°C75°F
8:457:507:006:185:365:024:33

Calculated from the 20°C (68°F) time using Ilford’s temperature compensation factors, not taken from a datasheet. Most B&W developers behave well between 18–24°C (64–75°F).

Mixing

Dilution300 ml (10.1 fl oz) (one 35mm roll)500 ml (16.9 fl oz) (one 120 roll)
StockUse as mixed, undilutedUse as mixed, undiluted
1+1150 ml developer + 150 ml water250 ml developer + 250 ml water

How they work together

Microphen
Fine grain, moderate acutance, normal contrast. Fine grain with an effective speed increase.
Rollei/Maco RPX 400
Rollei describes a high-speed panchromatic film with good edge sharpness, high resolving power and fine grain (RMS 14) on a triacetate base, for available-light, sports and reportage work.
Notes on this pairing
  • Push +1.

RPX 400 in other developers

Other films in Microphen