Development time

Rollei RPX 25 in Rodinal

6:00 at 20°C, 1+25 dilution, box speed.

Start timer · 6:00

Time

6:00

Standard

Dilution

1+25

Temperature

20°C

Box speed

ISO 25

B&W

All 3 times

Dilution	EI	Time	Temp	Agitation	Timer
1+25	25	6:00Not yet verified	20°C / 68°F	Standard	Start timer
1+50	25	10:00Not yet verified	20°C / 68°F	Standard	Start timer
1+100	25	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
7:30	6:43	6:00	5:24	4:48	4:19	3:54

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 25: Ultra-slow panchromatic with exceptional resolution and sharpness. Silver-rich emulsion. Formerly Agfa APX 25.
Notes on this pairing: Higher contrast.
Stand development: Agitate first minute, then leave undisturbed for 1 hour.

RPX 25 in other developers

D-76