How to Develop Black and White Film at Home

Developing black and white film at home takes about an hour, a few pieces of inexpensive equipment and three chemicals. You don't need a darkroom: only loading the film onto the reel must happen in the dark, and a changing bag handles that. This guide covers the whole process from a finished roll to hanging negatives.

What you need

A developing tank and reels. Paterson-style plastic tanks with self-loading reels are easiest to learn on; stainless steel tanks and reels use less chemistry and are very durable.
A changing bag, or a room that is completely dark.
A bottle opener to pop the end off 35mm cassettes, and scissors.
A thermometer accurate to about half a degree.
Measuring cylinders and storage bottles.
A timer. A phone works.
Chemicals: developer, stop bath (or plain water), fixer and a wetting agent.
Film clips and somewhere dust-free to hang the film.

Wear gloves and eye protection, work with ventilation, keep chemicals away from food and children, and read each product's safety sheet. Dispose of used fixer as your local rules require, since it carries dissolved silver.

Step 1: Load the film onto the reel

Practice first with a sacrificial roll in daylight until you can do it with your eyes closed. Then, in the changing bag with the tank, lid, reel, scissors and opener:

Open the 35mm cassette with the bottle opener and remove the spool. For 120, break the seal and separate the film from the backing paper.
Cut off the tapered leader square, and round the corners slightly so it feeds smoothly.
Feed the end into the reel's entry guides and ratchet the two halves back and forth to draw the film in. Hold film by the edges only.
Cut the film from the spool at the end, put the reel in the tank, and close the lid securely.

The tank is now light-tight, and the rest of the process happens in normal room light.

Step 2: Mix chemicals and check temperature

Mix developer to the dilution you have chosen, and stop bath and fixer according to their instructions. The standard development temperature is 68°F (20°C). Development times change with temperature, roughly 10 percent for each degree Celsius, so measure carefully and use the time-and-temperature chart for your developer if you can't hit 20°C exactly. Bring all chemicals and wash water close to the same temperature to avoid shocking the emulsion.

Look up the development time for your film, developer and dilution on the film's data sheet or a reference such as the Massive Dev Chart. The guide to developers explains how to choose one.

Step 3: Develop

Some photographers pre-wash with water for a minute; it is optional for most films. Then pour in the developer briskly, start the timer, tap the tank on the counter to dislodge air bubbles, and agitate.

A common agitation pattern is 4 gentle inversions over 10 seconds at the start and then 4 inversions every minute, tapping the tank after each. Whatever pattern you choose, keep it consistent; agitation affects contrast as much as time does. About 10 seconds before the time is up, start pouring the developer out.

Step 4: Stop

Pour in stop bath, or plain water, and agitate continuously for 30 to 60 seconds. Acid stop bath halts development immediately and keeps developer from carrying over into the fixer; several water rinses do nearly as well. Some films and staining developers specify a water stop.

Step 5: Fix

Pour in fixer and agitate for the first 30 seconds and then for a few seconds each minute. Typical rapid fixer times are 3 to 5 minutes; tabular-grain films like T-Max often need longer. A reliable test: put a scrap of undeveloped film leader in fixer and time how long it takes to clear. Fix the roll for twice that. After fixing, the film is no longer light sensitive and you can open the tank.

Fixer can usually be reused for many rolls. Keep a tally, and retest clearing time; when it doubles from fresh, replace it.

Step 6: Wash

Washing removes fixer so the negatives last. The Ilford method saves water: fill the tank with water at the same temperature, invert 5 times, drain; refill, invert 10 times, drain; refill, invert 20 times, drain. With a hypo clearing agent, washing time drops further. A running water wash of 10 minutes also works.

Step 7: Wetting agent and drying

A final rinse with a few drops of wetting agent, such as Kodak Photo-Flo at about 1:200 in distilled water, lets water sheet off without leaving spots. Don't overdo it, or it leaves streaks. Hang the film with a clip at each end in a dust-free place, a shower is ideal, and let it dry for a few hours. Avoid squeegeeing, which can scratch.

When dry, cut the strips and store them in archival sleeves. See storing film and negatives.

A quick reference

Step	Time	Agitation
Pre-wash (optional)	1 min	Continuous
Developer	Per data sheet at 68°F/20°C	First 10s, then 10s each minute
Stop bath or water	30 to 60s	Continuous
Fixer	Twice the clearing time, typically 3 to 5 min	First 30s, then 10s each minute
Wash	5/10/20 inversions, or 10 min running	As described
Wetting agent	30 to 60s	None, or one gentle inversion

Once you're comfortable, try pushing and pulling or stand development, and when you're ready for color, C-41 at home.