Development time

Ilford Ilford Delta 100 in Perceptol

15:00 at 20°C, stock dilution, box speed.

Start timer · 15:00

Time

15:00

Standard

Dilution

Stock

Temperature

20°C

Box speed

ISO 100

B&W

All 3 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	100	15:00	20°C / 68°F	Standard	Start timer
1+1	100	12:00Not yet verified	20°C / 68°F	Standard	Start timer
1+3	100	16:00Not yet verified	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
18:45	16:48	15:00	13:30	12:00	10:48	9:45

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

Perceptol: Moderate acutance, normal contrast. Extremely fine grain, optimised for enlargement.
Ilford Ilford Delta 100: Core-Shell crystal technology for extreme sharpness and virtually invisible grain. Clinical and precise look.
Notes on this pairing: CORRECTED from 540s per Ilford datasheet (15 min). Produces extremely fine grain.
Per Ilford technical data.

Ilford Delta 100 in other developers

ID-11