Development time

Kodak Portra 400 in Compard Digibase C-41

21:00 at 20°C, stock dilution, box speed.

Start timer · 21:00

Time

21:00

Standard

Dilution

Stock

Temperature

20°C

Box speed

ISO 400

C-41

All 4 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	400	3:15	37.8°C / 100°F	Standard	Start timer
Stock	400	2:00	45°C / 113°F	Standard	Start timer
Stock	400	13:00	25°C / 77°F	Standard	Start timer
Stock	400	21:00	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
26:15	23:31	21:00	18:54	16:48	15:07	13:39

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

How they work together

Kodak Portra 400: Widely regarded as the industry standard for professional colour work. Vision3 technology provides exceptionally fine grain and impressive exposure latitude.
Notes on this pairing: 100 °F (37.8 ±0.3 °C). Invert continuously for 15 s, then once every 30 s.
Rapid process at 45 °C.
Low-temperature option at 25 °C.
Low-temperature option at 20 °C.

Portra 400 in other developers

Adox C-TEC 41