Skip to main content

Development time

Harman Technology Kentmere Pan 400 in Perceptol

23:00 at 20°C (68°F), 1+1 dilution, EI 320 (−⅓ stop).

Start timer · 23:00
Time
23:00
Standard
Dilution
1+1
Temperature
20°C
68°F
Box speed
ISO 400
B&W

Development time

DilutionEITimeTempAgitationEvidenceTimer
1+1320−⅓ stop23:0020°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
28:4525:4623:0020:4218:2416:3414:57

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)
1+1150 ml developer + 150 ml water250 ml developer + 250 ml water

How they work together

Perceptol
Moderate acutance, normal contrast. Extremely fine grain, for when a loss of film speed is acceptable.
Harman Technology Kentmere Pan 400
Harman's budget ISO 400 line: general-purpose panchromatic film with a flat, clean negative that scans well; Harman says it has excellent push characteristics, with more visible grain than Pan 100 and slightly less contrast. 120 added December 2022.

Kentmere Pan 400 in other developers

Other films in Perceptol