Film specifications#
- Manufacturer
- Efke
- Film
- KB21 / R21 / PL21M
- Speed
- 100
- Process
- B&W
- Formats
- 135-36, 127, 120, 620, sheet film
- Base
- Triacetate
- Made in
- Yugoslavia
- Status
- Discontinued — replaced by KB 100 / R 100 / PL 100 M
Character & history#
Panchromatic classic 1950s style emulsion. Sheet film PL21M with retouchable back.
Description adapted from Wikipedia’s “List of discontinued photographic films” (CC BY-SA 4.0).
Exposure guide at ISO 100#
Sunny 16 for this film: f/16 at 1/100 s in bright sun. Negative film tolerates 2–3 stops of overexposure; slide film needs accuracy within about ⅓–½ stop.
| Light | f/2 | f/4 | f/8 | f/16 |
|---|---|---|---|---|
| EV 16 · Snow / beach, bright sun | — | — | 1/1000 s | 1/250 s |
| EV 15 · Bright sun | — | 1/2000 s | 1/500 s | 1/125 s |
| EV 14 · Hazy sun | — | 1/1000 s | 1/250 s | 1/60 s |
| EV 13 · Cloudy-bright | 1/2000 s | 1/500 s | 1/125 s | 1/30 s |
| EV 12 · Overcast / open shade | 1/1000 s | 1/250 s | 1/60 s | 1/15 s |
| EV 10 · Sunset | 1/250 s | 1/60 s | 1/15 s | 1/4 s |
| EV 8 · Bright interior | 1/60 s | 1/15 s | 1/4 s | 1 s |
| EV 5 · Home interior at night | 1/8 s | 0.5 s | 2 s | 8 s |
| EV 3 · City street at night | 0.5 s | 2 s | 8 s | 30 s |
Push & pull options#
Tell your lab how many stops you pushed or pulled so development is adjusted for the whole roll.
| Adjustment | Rate the film at | Effect |
|---|---|---|
| Pull 1 stop | EI 50 | Lower contrast, finer grain |
| Push 1 stop | EI 200 | More contrast and grain |
| Push 2 stops | EI 400 | Strong contrast, coarse grain, blocked shadows |
| Push 3 stops | EI 800 | Strong contrast, coarse grain, blocked shadows |
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.
Similar films#
Other black-and-white negative film around ISO 100.
- ADOX CHS 100 II ISO 100
- AgfaPhoto APX 100 ISO 100
- Argenti Pan-X ISO 100
- Film Photography Project BW 100 ISO 100
- Film Photography Project Derev Pan 100 ISO 100
- Film Photography Project Emulsion X ISO 100
- Film Photography Project Let It Snow ISO 100
- Film Photography Project Svema Foto 100 ISO 100
- Film Photography Project Tasma NK-2 ISO 100
- Film Photography Project WolfMan ISO 100
- Film Photography Project X-Ray Film ISO 100
- Film Washi 'F' ISO 100
- Film Washi 'K' ISO 100
- Film Washi 'P' ISO 100
- Film Washi 'V' ISO 100
- Film Washi 'Y' ISO 100
- Flic Film 'Wolfen 100' ISO 100
- Flic Film Flic UltraPan 100 ISO 100
More Efke films#
Frequently asked questions#
What ISO is Efke KB21 / R21 / PL21M?
100 — set your meter to ISO 100 for box speed.
Is Efke KB21 / R21 / PL21M still made?
No, it has been discontinued (1974–c1991).
How do I develop Efke KB21 / R21 / PL21M?
B&W process. Traditional black-and-white development (e.g. D-76/ID-11, HC-110, Rodinal, XTOL) — easy to do at home.
Is Efke KB21 / R21 / PL21M available in 35mm?
Yes — formats: 135-36, 127, 120, 620, sheet film.
Sources & licences#
- Wikipedia: List of discontinued photographic films — CC BY-SA 4.0
Last updated October 03, 2026 · How we calculate · Sources