Developing a Negative: Time, Temperature, Agitation

Everything up to the fixer happens in total darkness — a changing bag or a genuinely dark room. No safelight: film is sensitive to all visible light, unlike printing paper. **Practise with a sacrificial roll in daylight first.** Loading a reel by feel is the one genuinely awkward manual skill in the process, and learning it in the dark with a roll that matters is the wrong order. **Everything dry.** A damp reel will not take a film — it binds halfway and cannot be pushed or pulled. This is the commonest failure. **Lay out everything before the lights go off**: opener, scissors, reel, tank, lid. In the dark, a tool that is not where you left it is gone. **Cut the leader square** and slightly round the corners; a square corner catches in the reel's spiral. **Feel for the film buckling.** If it is not tracking, it bulges in the middle and will touch itself — and any part touching another part does not develop, leaving a clear blotch. **Lid on before the lights go on.** Then everything after is done in the light.

Agitation replaces the exhausted developer at the film surface with fresh developer. Without it, the chemistry next to a dense area is used up and development there stops. **The standard scheme:** continuous inversions for the first 30 seconds, then four inversions every minute, with a firm tap on the bench after each round to dislodge bubbles. **Too little** gives **bromide drag** — streaks running down from dense areas, where exhausted developer has sunk and held back development below them. Most visible against a plain sky, and unmistakable once seen. **Too much** raises contrast and can give uneven development along the edges, where the sprocket holes let developer surge through more freely than in the middle. **Stand development** is the deliberate extreme: very dilute developer, an hour or more, almost no agitation. The shadows keep developing while the highlights exhaust their local developer and stop, which compresses an enormous brightness range. It also gives bromide drag if the little agitation it does get is not even. **Be consistent.** The exact scheme matters less than using the same one every time, because a time is only meaningful alongside the agitation it was measured with.

**Mix into water, never water into concentrate**, for the same reason as any other chemistry — and with the same eye protection and ventilation. **One-shot or replenished.** A one-shot developer is diluted from concentrate, used once and thrown away. It is the reliable choice, because every roll gets the same fresh chemistry. A replenished or reused stock developer is cheaper and needs a record of how many rolls it has done plus a correction, and the record is the whole of the technique. **Developer dies in air, not in use.** A part-used bottle oxidises and goes brown. Store full, in small bottles, and treat a brown developer as dead: it will give thin negatives and no warning. **Water quality matters more than people expect.** Hard water can give a scum on the negative; very cold tap water changes the time. Let it stand to reach room temperature, and use the same source each time. **Write down what was done.** Film, developer, dilution, temperature, time, agitation scheme, and how it came out. Without it, a thin negative has half a dozen possible causes; with it, usually one.