Development time

Ilford Delta 400 in 510-Pyro

22:00 at 20°C, 1+100 dilution, box speed.

Start timer · 22:00

Time

22:00

Stand

Dilution

1+100

Temperature

20°C

Box speed

ISO 400

B&W

All 2 times

Dilution	EI	Time	Temp	Agitation	Timer
1+100	400	22:00	20°C / 68°F	Stand	Start timer
1+100	400	9:30	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
27:30	24:38	22:00	19:48	17:36	15:50	14:18

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 Delta 400: Modern T-grain film with fine grain and high sharpness. Core-shell crystal technology provides excellent detail. More contrast than HP5 with less pushability.
Notes on this pairing: Hartung semi-stand: 1 min continuous inversion, then one inversion at 10, 20, 30 min.
Rotary processor or tray, continuous agitation.

Delta 400 in other developers

D-76