1. Unit 57 – Photography Film developing

2. Developing film is a bit like baking a cake.
You need to have all the right ingredients and you need to follow the recipe carefully.

3. Loading the developing tank
The film needs to be loaded on to the spiral in complete darkness.
The spiral needs to be placed in the tank and the lid fitted before you turn on the light.

4. Preparing the chemicals
You need to have the right amount of developer, stop bath and fixer ready before you start processing the film.
There is a guide on the bottom of the developing tank to help.

5. Developer There are lots of different developers available to use.
Each has its own characteristics and its own development time.
You can find information about dilutions and development times from the manufacturers’ websites or from The Massive Dev Chart at

6. Developer must be mixed to the right concentration and the right temperature.
You must use measuring cylinders and a thermometer to check – otherwise you may over-develop or under-develop your film.
Developer is usually mixed with water to make a working solution. Dilutions are expressed as a ratio – e.g. 1+1
1+1 means you use equal amounts or water and developer
1+2 means you use twice as much water as developer
1+3 means you use three times as much water as developer

7. How much water would you use to make 400ml of working solution at a dilution of 1+1?

8. The temperature of the solution has a huge effect on development times
The temperature of the solution has a huge effect on development times. It should be 20° Centigrade.
If it is too hot the film will be over-developed.
If it is too cold the film will be under-developed.
You can use charts to look up modified development times if the solution is just a few degrees out.

9. Stop bath
Stop bath is a weak acid which is designed to stop the development process.
It also helps to make fixer last longer.
It can be used many times and sometimes contains an indicator which changes colour when the solution is exhausted

10. Fixer
Fixer dissolves the unexposed silver halides from the film emulsion to preserve or ‘fix’ the image.
Fixer can be re-used but will eventually become exhausted.
If your film has a milky appearance it has not been properly fixed.

11. When you have you chemicals prepared and your film loaded into the processing tank you can begin.
Step 1: Start your timer. Pour the developer into the tank, put the watertight lid on, and agitate for 30 seconds. Tap the tank smartly to dislodge air bubbles.
Step 2: Continue agitating for 10 seconds every minute until the development time is complete.
Step 3: Pour out the developer and pour in the stop bath. Agitate for 30 seconds.
Step 4: Pour out the stop bath and pour in the fixer. Agitate for 30 seconds and then for 10 seconds every minute until fixing is complete.
Step 5: Take the spiral out of the processing tank and place it in the wash bath. Recycle the stop bath and fixer. Pour the developer away.

12. Step 6: Clean the processing tank carefully to remove all traces of fixer.
Step 7: When the film has finished washing place the spiral back in the processing tank and fill the tank with clean water. Add a few drops of wetting agent and move the spiral up and down for a few second to break the surface tension of the water.
Step 8: Remove the film from the spiral and ‘squeegee’ off any excess water with wetted fingers. Hang the film up to dry in the drying cabinet.
Step 9: When the film is bone dry, cut it into strips and put it into negative bags ready for printing.