Development time

Kodak Portra 400 in Adox C-TEC 41

3:15 at 38°C, stock dilution, box speed.

Start timer · 3:15

Time

3:15

Standard

Dilution

Stock

Temperature

38°C

Box speed

ISO 400

C-41

All 4 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	400	3:15	38°C / 100°F	Standard	Start timer
Stock	800+1 stop	3:45	38°C / 100°F	Standard	Start timer
Stock	1600+2 stops	4:15	38°C / 100°F	Standard	Start timer
Stock	400	8:00	30°C / 86°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

Colour developers run at 38°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: Fresh kit, first films. Agitate continuously for 30 s, then one gentle tilt every 15 s; rotary also fine. Time rises 15 s per later batch (3:30, 3:45, 4:00).
Push +1: colour development extended 30 s per stop at 38 °C.
Push +2: colour development extended 30 s per stop at 38 °C.
30 °C option for home use, first film.

Portra 400 in other developers

Bellini C-41 Monopart Kit