Developing Tank

Overview

The developing tank is the single piece of equipment that made home processing practical. Film goes onto a reel in darkness, the reel goes into the tank, the lid goes on — and from that moment everything can be done with the lights up.

There are two families. Plastic tanks with adjustable reels load by ratcheting the film on, and accept both 35mm and 120. Stainless steel tanks with steel reels are more durable, easier to clean and hold temperature better, but steel reels need a confident, unhurried loading technique or the film jams.

Capacity matters more than it looks. A two-reel tank used with one reel has more chemistry than you need but leaves air space that makes inversion agitation less even. Match the tank to how many rolls you actually process at a time.

What it does well

• Develop in daylight once the lid is on
• Adjustable plastic reels take both 35mm and 120
• Funnel lid lets you pour chemistry in and out without removing it
• Steel tanks hold temperature more stably in a water bath
• Stackable and easy to store

Safety notes

Working notes

• Practise loading a sacrificial roll with your eyes closed until you can do it without thinking.
• Always use the same volume of chemistry as the tank needs — too little leaves the top reel dry.
• Fill the tank with water at working temperature and let it stand for five minutes before you start.
• Rinse the lid's light trap after every session; dried fixer crystals there will leak light.

Compatible with