Skip to main content

Development time

Ilford FP4 Plus in XTOL

8:30 at 20°C (68°F), stock dilution, box speed.

Start timer · 8:30
Time
8:30
Standard
Dilution
Stock
Temperature
20°C
68°F
Box speed
ISO 125
B&W

All 2 times

DilutionEITimeTempAgitationEvidenceTimer
Stock1258:3020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
Stock200+⅔ stop10:0020°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
10:389:318:307:396:486:075:32

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

How they work together

XTOL
Fine grain, high acutance, full film speed, normal contrast. Excellent shadow detail with wide latitude.
Ilford FP4 Plus
Often considered a benchmark for medium speed B&W. Notable sharpness and fine grain. Well-suited for high-quality enlargements.

FP4 Plus in other developers

Other films in XTOL