Development time

Kodak Tri-X 400 in Rodinal

7:00 at 20°C, 1+25 dilution, box speed.

Start timer · 7:00

Time

7:00

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	7:00Not 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
8:45	7:50	7:00	6:18	5:36	5:02	4:33

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.
Kodak Tri-X 400: A classic photojournalism film with a long heritage. Known for its distinctive gritty grain, high contrast, and strong push-processing capability.
Notes on this pairing: Higher contrast, shorter time. Per R09 bottle instructions.
High sharpness and grain structure.
Stand development: Agitate first minute, then leave undisturbed for 1 hour.

Tri-X 400 in other developers

D-76