Development time

Ilford FP4 Plus in ID-11

8:30 at 20°C, stock dilution, box speed.

Start timer · 8:30

Time

8:30

Standard

Dilution

Stock

Temperature

20°C

Box speed

ISO 125

B&W

All 5 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	125	8:30	20°C / 68°F	Standard	Start timer
1+1	125	11:00	20°C / 68°F	Standard	Start timer
1+3	125	17:00Not yet verified	20°C / 68°F	Standard	Start timer
Stock	200+⅔ stop	10:00	20°C / 68°F	Standard	Start timer
1+1	200+⅔ stop	15:00	20°C / 68°F	Standard	Start timer

EI is the speed the film was rated at when shooting. Times marked “not yet verified” come from secondary sources and haven’t been checked against a manufacturer datasheet.

Other temperatures

18°C	19°C	20°C	21°C	22°C	23°C	24°C
10:38	9:31	8:30	7:39	6:48	6:07	5:32

Calculated from the 20°C time using Ilford’s temperature compensation factors, not taken from a datasheet. Most B&W developers behave well between 18°C and 24°C.

Mixing

Dilution	300 ml (one 35mm roll)	500 ml (one 120 roll)
Stock	Use as mixed, undiluted	Use as mixed, undiluted
1+1	150 ml developer + 150 ml water	250 ml developer + 250 ml water
1+3	75 ml developer + 225 ml water	125 ml developer + 375 ml water

How they work together

ID-11: Fine grain, moderate acutance, full film speed, normal contrast. Excellent balance of fine grain, sharpness, and tonal rendition.
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: Maximum sharpness dilution. Use immediately after mixing.
Pushed +2/3 stop.
Pushed +2/3 stop. One-shot use.

FP4 Plus in other developers

Ilfosol 3