Development time

Ilford HP5 Plus in 510-Pyro

9:00 at 20°C, 1+100 dilution, box speed.

Start timer · 9:00

Time

9:00

Standard

Dilution

1+100

Temperature

20°C

Box speed

ISO 400

B&W

All 2 times

Dilution	EI	Time	Temp	Agitation	Timer
1+100	400	9:00	20°C / 68°F	Standard	Start timer
1+100	400	7:30	21°C / 70°F	Continuous	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
11:15	10:05	9:00	8:06	7:12	6:29	5:51

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+100	3 ml developer + 297 ml water	5 ml developer + 495 ml water

How they work together

510-Pyro: Very-high acutance, full film speed, compensating contrast. Exceptional highlight control with subtle staining.
Ilford HP5 Plus: A robust, all-purpose film. Slightly lower contrast than Tri-X with excellent shadow detail and pushability.
Notes on this pairing: Ilford agitation (spiral tank).
Rotary processor or tray, continuous agitation.

HP5 Plus in other developers

Df96 Monobath