Development time

Kodak Portra 400 in Unicolor C-41

3:30 at 38.9°C, stock dilution, box speed.

Start timer · 3:30

Time

3:30

Standard

Dilution

Stock

Temperature

38.9°C

Box speed

ISO 400

C-41

All 5 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	400	3:30	38.9°C / 102°F	Standard	Start timer
Stock	800+1 stop	4:23	38.9°C / 102°F	Standard	Start timer
Stock	1600+2 stops	5:15	38.9°C / 102°F	Standard	Start timer
Stock	400	8:00	32.2°C / 90°F	Continuous	Start timer
Stock	400	17:30	23.9°C / 75°F	Continuous	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

Colour developers run at 38.9°C with a tight tolerance of around ±0.3°C, so there’s no reliable temperature chart. If you can’t hold the temperature, follow your kit’s instructions for its lower-temperature times.

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: Hand tank at 102 °F: continuous for 10 s, then 4 inversions every 30 s. Rotary drum time at 104 °F is also 3.5 min.
Push +1: development time x1.25 (instructions print 3.5 x 1.25 as '4.40 min'; exact value is 4 min 22.5 s).
Push +2: development time x1.5 (5.25 min).
Rotary drum at 90 °F.
Rotary drum at 75 °F.

Portra 400 in other developers

Adox C-TEC 41