Shooting HP5 at 1600: what the sheet actually lists
HP5 Plus is rated at ISO 400, but Ilford's datasheet has columns up to EI 3200. Shooting at a higher EI underexposes the film; the longer development in those columns builds the contrast back. Shadow detail you didn't expose for won't come back, so expect blacker shadows and more grain.
Published times, 20 °C
| Developer | EI 400 | 800 | 1600 | 3200 |
|---|---|---|---|---|
| Ilfotec DD-X 1+4 | 9 | 10 | 13 | 20 |
| Microphen stock | 6½ | 8 | 11 | 16 |
| ID-11 stock | 7½ | 10½ | 14 | – |
| Kodak Xtol stock | 8 | 11 | 14 | 19 |
A dash means the sheet gives no time for that speed. Ilford HP5 Plus technical information, Nov 2018.
Things I'd keep in mind
- Decide the EI before you load the roll and shoot the whole roll at it. You can't develop half a roll longer.
- Write the EI on the cassette or the backing paper. Future-you will not remember.
- Not every developer goes to 3200. On this sheet DD-X, Microphen, Ilfotec HC at 1+15 and Kodak Xtol are among those that do.
- Several Ilford sheets also have a short "accidental exposure" table for rolls shot at the wrong speed by mistake.
- Delta 400 has a similar ladder; filter the times table to see it.
Sources
- HP5 Plus technical information, Ilford (HARMAN technology), Nov 2018.