Color slide film · Discontinued

Ilford Colour Film F

Ilford Colour Film F is a color slide film rated at ISO 20, developed in Ilford. Below: specs, an exposure guide and similar stocks.

ISO 20IlfordDiscontinued135
ISO 20
Box speed
Color slide
Type
Ilford
Process
Discontinued
Status
1956–1960
Years made

Film specifications#

Manufacturer
Ilford
Film
Colour Film F
Speed
20
Process
Ilford
Formats
135
Base
Triacetate
Made in
UK
Status
Discontinued

Character & history#

General purpose slide film for clear flash bulbs.

Description adapted from Wikipedia’s “List of discontinued photographic films” (CC BY-SA 4.0).

Exposure guide at ISO 20#

Sunny 16 for this film: f/16 at 1/20 s in bright sun. Negative film tolerates 2–3 stops of overexposure; slide film needs accuracy within about ⅓–½ stop.

Lightf/2f/4f/8f/16
EV 16 · Snow / beach, bright sun1/3200 s1/800 s1/200 s1/50 s
EV 15 · Bright sun1/1600 s1/400 s1/100 s1/25 s
EV 14 · Hazy sun1/800 s1/200 s1/50 s1/13 s
EV 13 · Cloudy-bright1/400 s1/100 s1/25 s1/6 s
EV 12 · Overcast / open shade1/200 s1/50 s1/13 s0.3 s
EV 10 · Sunset1/50 s1/13 s0.3 s1.3 s
EV 8 · Bright interior1/13 s0.3 s1.3 s5 s
EV 5 · Home interior at night0.6 s2.5 s10 s30 s
EV 3 · City street at night2.5 s10 s30 s> 1 min

Long exposures#

Most films suffer reciprocity failure beyond about 1 second: they need more exposure than the meter says. As a rule of thumb add ⅓–1 stop for 1–10 s and 1–2 stops beyond 10 s for older emulsions; modern T-grain films (and Fuji Acros) need much less. Check the manufacturer's datasheet.

More Ilford films#

Frequently asked questions#

What ISO is Ilford Colour Film F?

20 — set your meter to ISO 20 for box speed.

Is Ilford Colour Film F still made?

No, it has been discontinued (1956–1960).

How do I develop Ilford Colour Film F?

Ilford process.

Is Ilford Colour Film F available in 35mm?

Yes — formats: 135.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources