Development time

Ilford HP5 Plus in Ilfosol 3

6:30 at 20°C, 1+9 dilution, box speed.

Start timer · 6:30

Time

6:30

Standard

Dilution

1+9

Temperature

20°C

Box speed

ISO 400

B&W

All 3 times

Dilution	EI	Time	Temp	Agitation	Timer
1+9	400	6:30	20°C / 68°F	Standard	Start timer
1+9	800+1 stop	8:00	20°C / 68°F	Standard	Start timer
1+9	1600+2 stops	11:00	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
8:08	7:17	6:30	5:51	5:12	4:41	4:14

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)
1+9	30 ml developer + 270 ml water	50 ml developer + 450 ml water

How they work together

Ilfosol 3: High acutance, full film speed, medium-high contrast. Good general purpose results.
Ilford HP5 Plus: A robust, all-purpose film. Slightly lower contrast than Tri-X with excellent shadow detail and pushability.
Notes on this pairing: Pushed +1 stop.
Pushed +2 stops.

HP5 Plus in other developers

Df96 Monobath