Home-developing HP5: the three mistakes I kept making
I have developed somewhere around eighty rolls of HP5 at home now. The process is not hard, and most of the guides online are correct. My problem was never the guide. It was me, standing in a small bathroom in August, deciding that something was probably fine.
1. Temperature drift
The datasheet times assume 20°C. In summer my tap water comes out at 24°C and the bathroom is warmer than that. For a while I compensated by shortening the time "a bit", which is not a number. Now I keep a jug of water in the fridge, mix the developer down to 20°C, and stand the tank in a bowl of water at the same temperature. Boring, and it fixed most of my blocked highlights.
2. Too much agitation
I used to invert the tank like I was mixing a cocktail. The negatives came out with dense edges and a faint surge mark near the sprocket holes. The fix was to slow down: four gentle inversions in the first minute, then four every minute after, each one taking about two seconds. I count out loud, which my neighbours probably enjoy.
3. Pulling the film out too early
This is the one that hurt. After the fixer, I was always in a hurry to look at the negatives, so I gave the wash two or three minutes and hung the film to dry. A year later a few strips had a brownish tint. Now the film gets the full wash and a final rinse with a drop of wetting agent, and I go and make tea instead of hovering.
My current routine
- Developer at 20°C, times from the datasheet, plus one minute for very flat light
- Stop bath for one minute, fixer for five, with the same slow agitation
- Ten minutes of running water, then the wetting agent
- Dry overnight in the shower with the door closed, to keep the dust down
None of this is new. It just took me eighty rolls to actually do it every time.