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Development time

Ilford Ilford Delta 100 in Ilfotec HC

6:00 at 20°C (68°F), 1+31 dilution, box speed.

Start timer · 6:00
Time
6:00
Standard
Dilution
1+31
Temperature
20°C
68°F
Box speed
ISO 100
B&W

All 6 times

DilutionEITimeTempAgitationEvidenceTimer
1+3150−1 stop5:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+311006:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+31200+1 stop8:0020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+4750−1 stop5:3020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+471007:3020°C / 68°FStandardManufacturerChecked Oct 2026Start timer
1+47200+1 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
7:306:436:005:244:484:193:54

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+319.4 ml developer + 291 ml water16 ml developer + 484 ml water
1+476.3 ml developer + 294 ml water10 ml developer + 490 ml water

How they work together

Ilfotec HC
Not stated acutance, Not stated contrast. Not stated.
Ilford Ilford Delta 100
Core-Shell crystal technology for extreme sharpness and virtually invisible grain. Clinical and precise look.
Notes on this pairing
  • One-shot dilution.

Ilford Delta 100 in other developers

Other films in Ilfotec HC