On subjects having violent contrasts where it is necessary to show detail in both highlights and shadows, an acid-amidol developer can be used.
| Ingredient | Quantity | |
|---|---|---|
| Sodium bisulphite | 12 | grams |
| Amidol | 10 | grams |
| Sodium sulphite | 8 | grams |
| Water to make | 1 | liter |
| Mix chemicals in order. | ||
With this developer at 18.5°C, the image usually appears in 10 to 15 minutes and the total time of development is usually about 2 hours though it can be carried on for 12 hours if necessary.