Development time

Ilford Ortho Plus in Microphen

9:00 at 20°C, stock dilution, box speed.

Start timer · 9:00

Time

9:00

Standard

Dilution

Stock

Temperature

20°C

Box speed

ISO 80

B&W

All 2 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	80	9:00	20°C / 68°F	Standard	Start timer
1+1	80	11:30	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
11:15	10:05	9:00	8:06	7:12	6:29	5:51

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
1+1	150 ml developer + 150 ml water	250 ml developer + 250 ml water

How they work together

Microphen: Fine grain, moderate acutance, normal contrast. Good with effective speed increase.
Ilford Ortho Plus: Orthochromatic film sensitive to blue and green only. Can be handled under red safelight. Reds and oranges render dark.
Notes on this pairing: Pictorial contrast (Gbar 0.62).

Ortho Plus in other developers

D-76