Development time
Ilford FP4 Plus in Ilfotec HC
4:00 at 20°C (68°F), 1+15 dilution, box speed.
Start timer · 4:00- Time
- 4:00
- Dilution
- 1+15
- Temperature
- 20°C
- Box speed
- ISO 125
All 7 times
| Dilution | EI | Time | Temp | Agitation | Evidence | Timer |
|---|---|---|---|---|---|---|
| 1+15 | 125 | 4:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+15 | 200+⅔ stop | 5:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+31 | 50−1⅓ stops | 6:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+31 | 125 | 8:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+31 | 200+⅔ stop | 9:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+47 | 50−1⅓ stops | 8:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start timer |
| 1+47 | 125 | 12:00 | 20°C / 68°F | Standard | ManufacturerChecked Oct 2026 | Start 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°F | 19°C66°F | 20°C68°F | 21°C70°F | 22°C72°F | 23°C73°F | 24°C75°F |
|---|---|---|---|---|---|---|
| 5:00 | 4:29 | 4:00 | 3:36 | 3:12 | 2:53 | 2:36 |
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
| Dilution | 300 ml (10.1 fl oz) (one 35mm roll) | 500 ml (16.9 fl oz) (one 120 roll) |
|---|---|---|
| 1+15 | 19 ml developer + 281 ml water | 31 ml developer + 469 ml water |
| 1+31 | 9.4 ml developer + 291 ml water | 16 ml developer + 484 ml water |
| 1+47 | 6.3 ml developer + 294 ml water | 10 ml developer + 490 ml water |
How they work together
- Ilfotec HC
- Not stated acutance, Not stated contrast. Not stated.
- Ilford FP4 Plus
- Often considered a benchmark for medium speed B&W. Notable sharpness and fine grain. Well-suited for high-quality enlargements.
- Notes on this pairing
- One-shot dilution.
FP4 Plus in other developers
510-Pyro
20:25
1+100 · EI 125 · 20°C · 2 variants
D-76
8:00
Stock · EI 125 · 20°C · 9 variants
Diafine
6:00
Stock · EI 250 · 20°C
HC-110
4:30
1+15 · EI 125 · 20°C · 5 variants
ID-11
8:30
Stock · EI 125 · 20°C · 8 variants
Ilfosol 3
4:15
1+9 · EI 125 · 20°C · 3 variants
Ilfotec DD-X
10:00
1+4 · EI 125 · 20°C · 3 variants
Ilfotec LC29
4:00
1+9 · EI 125 · 20°C · 7 variants
Other films in Ilfotec HC
Ilford HP5 Plus
3:30
1+15 · EI 400 · 20°C · 8 variants
Ilford Delta 3200
8:00
1+15 · EI 3200 · 20°C · 7 variants
Ilford Delta 400
7:30
1+31 · EI 400 · 20°C · 11 variants
Harman Technology Kentmere Pan 400
4:30
1+15 · EI 400 · 20°C · 4 variants
Harman Technology Kentmere Pan 100
4:00
1+15 · EI 100 · 20°C · 7 variants
Ilford Ilford Delta 100
6:00
1+31 · EI 100 · 20°C · 6 variants
Ilford Pan F Plus 50
4:00
1+31 · EI 50 · 20°C · 2 variants
Ilford Ortho Plus
4:00
1+15 · EI 80 · 20°C · 2 variants