Color negative film · Discontinued

Efke Color NM20

Efke Color NM20 is a color negative film rated at ISO 80, developed in C-41. Below: specs, an exposure guide and similar stocks.

ISO 80C-41Discontinued135120
ISO 80
Box speed
Color negative
Type
C-41
Process
Discontinued
Status
1972–1977
Years made

Film specifications#

Manufacturer
Efke
Film
Color NM20
Speed
80
Process
C-41
Formats
135, 120
Base
Triacetate
Made in
Italy, Yugoslavia
Status
Discontinued — replaced by Color NM21

Character & history#

Masked color negative film for daylight. Rebranded 3M Color Print (C-41).

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

Exposure guide at ISO 80#

Sunny 16 for this film: f/16 at 1/80 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 sun—1/3200 s1/800 s1/200 s
EV 15 · Bright sun—1/1600 s1/400 s1/100 s
EV 14 · Hazy sun1/3200 s1/800 s1/200 s1/50 s
EV 13 · Cloudy-bright1/1600 s1/400 s1/100 s1/25 s
EV 12 · Overcast / open shade1/800 s1/200 s1/50 s1/13 s
EV 10 · Sunset1/200 s1/50 s1/13 s0.3 s
EV 8 · Bright interior1/50 s1/13 s0.3 s1.3 s
EV 5 · Home interior at night1/6 s0.6 s2.5 s10 s
EV 3 · City street at night0.6 s2.5 s10 s30 s

Push & pull options#

Tell your lab how many stops you pushed or pulled so development is adjusted for the whole roll.

AdjustmentRate the film atEffect
Pull 1 stopEI 40Lower contrast, finer grain
Push 1 stopEI 160More contrast and grain
Push 2 stopsEI 320Strong contrast, coarse grain, blocked shadows
Push 3 stopsEI 640Strong contrast, coarse grain, blocked shadows
Developing C-41: Standard colour-negative chemistry available at almost every lab and in home kits (Tetenal/Cinestill Cs41).

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 Efke films#

Frequently asked questions#

What ISO is Efke Color NM20?

80 — set your meter to ISO 80 for box speed.

Is Efke Color NM20 still made?

No, it has been discontinued (1972–1977).

How do I develop Efke Color NM20?

C-41 process. Standard colour-negative chemistry available at almost every lab and in home kits (Tetenal/Cinestill Cs41).

Is Efke Color NM20 available in 35mm?

Yes — formats: 135, 120.

Sources & licences#

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