Development time

Rollei RPX 400 in Rodinal

12:00 at 20°C, 1+25 dilution, box speed.

Start timer · 12:00

Time

12:00

Standard

Dilution

1+25

Temperature

20°C

Box speed

ISO 400

B&W

All 3 times

Dilution	EI	Time	Temp	Agitation	Timer
1+25	400	12:00Not yet verified	20°C / 68°F	Standard	Start timer
1+50	400	13:00Not yet verified	20°C / 68°F	Standard	Start timer
1+100	400	60:00Not yet verified	20°C / 68°F	Stand	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
15:00	13:26	12:00	10:48	9:36	8:38	7:48

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+25	12 ml developer + 288 ml water	19 ml developer + 481 ml water
1+50	5.9 ml developer + 294 ml water	9.8 ml developer + 490 ml water
1+100	3 ml developer + 297 ml water	5 ml developer + 495 ml water

How they work together

Rodinal: Prominent grain, high acutance, full film speed, variable contrast. Sharp, dramatic, distinct edge effects.
Rollei RPX 400: High-speed panchromatic with good edge sharpness and high resolving power. Wide tonal range ideal for sports and reportage.
Notes on this pairing: Per Rollei RPX 400 datasheet.
Stand development: Agitate first minute, then leave undisturbed for 1 hour.

RPX 400 in other developers

D-76