Notes
Written up from my notebook when I put this site together, with the source for every number.
- Twenty degrees, and the tap that won't give it to youEvery time on a datasheet assumes 20 °C. Here's how I correct for a warm or cold bath, and where the correction comes from.
- How to read a development tableMeter settings, 1+4 versus 1:4, what "intermittent agitation" means in practice, and the 15% rule nobody reads.
- Stop, fix, and the five-ten-twenty washThe steps after the developer, from Ilford's own sheets, including the wash that uses three tank-fills of water instead of ten minutes of running tap.
- Long exposures and the one-line reciprocity formulaPast one second, film needs more exposure than the meter says. Ilford publishes a factor for each film, and the maths fits on a phone calculator.
- Shooting HP5 at 1600: what the sheet actually lists"Pushing" is just developing longer for a film you underexposed on purpose. Ilford publishes the times; here they are side by side.