Film specifications#
- Manufacturer
- Agfa
- Film
- Agfacolor/Agfachrome CT18
- Type
- Color slide film
- Speed
- 50
- Process
- AP 41
- Formats
- 110, 126, 135, Rapid, 127, 120, 620
- Base
- Triacetate
- Made in
- Germany
- Status
- Discontinued — replaced by Agfachrome CT 64
Character & history#
General purpose color reversal film for daylight. Renamed to Agfachrome in 1978. Warm pleasing colors, but not very stable in long-term storage. 110 and 126 formats had speed of ISO 64/19°. 110 film was sold as "Agfachrome Pocket Special" until c1982.
Description adapted from Wikipedia’s “List of discontinued photographic films” (CC BY-SA 4.0).
Exposure guide at ISO 50#
Sunny 16 for this film: f/16 at 1/50 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 | — | 1/2000 s | 1/500 s | 1/125 s |
| EV 15 · Bright sun | — | 1/1000 s | 1/250 s | 1/60 s |
| EV 14 · Hazy sun | 1/2000 s | 1/500 s | 1/125 s | 1/30 s |
| EV 13 · Cloudy-bright | 1/1000 s | 1/250 s | 1/60 s | 1/15 s |
| EV 12 · Overcast / open shade | 1/500 s | 1/125 s | 1/30 s | 1/8 s |
| EV 10 · Sunset | 1/125 s | 1/30 s | 1/8 s | 0.5 s |
| EV 8 · Bright interior | 1/30 s | 1/8 s | 0.5 s | 2 s |
| EV 5 · Home interior at night | 1/4 s | 1 s | 4 s | 15 s |
| EV 3 · City street at night | 1 s | 4 s | 15 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.
Similar films#
Other color slide film around ISO 50.
- Fujifilm Fujichrome Velvia 50 ISO 50
- 3M Ferrania CR50A ISO 50 · disc.
- ADOX C 18 ISO 50 · disc.
- Agfa Agfachrome 50 RS ISO 50 · disc.
- Agfa Agfachrome 50L Professional ISO 50 · disc.
- Agfa Agfachrome 50S Professional ISO 50 · disc.
- Agfa Agfachrome RSX 50 ISO 50 · disc.
- Agfa Agfachrome RSX II 50 ISO 50 · disc.
- Ferrania Ferraniacolor Dia 28 ISO 50 · disc.
- Foma Fomachrom D 18 ISO 50 · disc.
- Foma Fomachrom-II D 18 ISO 50 · disc.
- Forte Fortechrom ISO 50 · disc.
- Fujifilm Fujichrome 50 ISO 50 · disc.
- Fujifilm Fujichrome 50 Professional D ISO 50 · disc.
- Fujifilm Fujichrome Fortia / Fortia SP ISO 50 · disc.
- Fujifilm Fujichrome Velvia ISO 50 · disc.
- Fujifilm Fujicolor Reversal Professional Daylight Type ISO 50 · disc.
- Ilford Ilfochrome 50 ISO 50 · disc.
More Agfa films#
Frequently asked questions#
What ISO is Agfa Agfacolor/Agfachrome CT18?
50 — set your meter to ISO 50 for box speed.
Is Agfa Agfacolor/Agfachrome CT18 still made?
No, it has been discontinued (1958–1984).
How do I develop Agfa Agfacolor/Agfachrome CT18?
AP 41 process.
Is Agfa Agfacolor/Agfachrome CT18 available in 35mm?
Yes — formats: 110, 126, 135, Rapid, 127, 120, 620.
Sources & licences#
- Wikipedia: List of discontinued photographic films — CC BY-SA 4.0
Last updated October 03, 2026 · How we calculate · Sources