Link to Part 1 in case you missed it…

There are essentially five things you’ll need to do to develop your black and white film:

  1. You’ll need to load it into the developing tank in the dark. That means a light-tight changing bag – I’ll go through this bit later – I’ll add a link when I’ve written it / filmed it.
  2. You’ll need to add developer to develop the film for a set amount of time.
  3. You’ll need to stop the process.
  4. You’ll need to fix the film.
  5. You’ll need to rinse the film.

Then, when it’s dry, you can scan it or print from it.

In this post we’re looking at how to prepare and mix up the chemicals for steps 2, 3, 4 and 5 and how to work out how long each stage will last, as mixing the chemicals is the first thing I do. I’ll go through the actual process of development in a separate post.


The Film Processing Chart

As a standard film that I find easy to get hold of in bulk I use a lot of Ilford HP5 plus at 400 ISO. So, let’s look at the Ilford film processing chart for how to process this. I’ve highlighted the bits I need for my film in yellow.

scan for candn blog 3
Ilford Film Processing Chart used for educational purposes


Reading the Chart

The chart lists the films along the top and the developers at the left hand side. So going along the top line until I find my film – HP5 Plus, gives me options for the different ISO options this film is available in. I’m looking at how to develop ISO 400 film. Next, I look for my developer which is Ilfosol 3. There are two numbers next to this that indicate how  to dilute the developer (you don’t use it neat, you have to mix it with water first). What do these mean? These are the ratio of chemical to water.

If you read horizontally from these developer ratios until you get to the column for HP5 Plus 400, you’ll see a number; this is the time, in minutes, that developing will take. If I use developer at a ratio of 1 part developer to 9 parts water then it will take 6.5 minutes to develop the film.  If I use developer at a ratio of 1 part developer to 14 parts water it will take 11 minutes.

Obviously using less developer is cheaper, but I tend to go with the shorter time.


Splitting it into Parts: 

The Developer

Okay, lets work out how much developer we need:

I’ve already said my tank says 1x35mm = 290ml on the base; that’s the amount of liquid that needs to be sloshing about for the 35mm film to sit in. I round that up to 300ml because the maths and measurements are easier that way.

Working out ratios is easy. It’s just splitting everything into equal parts.

I need 300ml of liquid.

I need a total of 10 parts (1+9).

Each part will be equal to 300ml /10 = 30ml

One part developer to 9 parts water means that I will need (1x 30ml) of developer and (9 x 30ml) of water, so 30ml developer and 270ml of water.

Make a note of your development time. Mine is six and a half minutes. 

A Note on Temperature

The water needs to be at a temperature of 20 degrees. I’ve highlighted that on the chart – it’s in the top left corner. I find it difficult to get water from the tap at the correct temperature, so I usually measure out the water and leave it to stand for a couple of hours. 20 degrees is a nice room temperature so that usually works perfectly for me. However, if you can’t get water to the correct temperature you can adjust your development time. Essentially for warmer water you need less development time, for colder you need more. I wouldn’t go below 18 degrees for your water temperature though. There are instructions for water at 24 degrees on the film pack, and the chart works the same as above. (You can see an example in part 1). There are helpful charts and instructions in Michael Langford’s Darkroom Handbook about adjusting development time for temperature. If you’re planning on doing a lot of developing and printing it’s certainly a book you should invest in.

I measure out my water for each part and leave it to stand in an accordion bottle, then I add the chemical to it and swill it around gently to mix it. Don’t shake it. Just so you know,

you can do all of this bit in the light; it doesn’t have to be done in a darkroom.

None of the chemicals for developing film have to be prepared in the dark. However, if you’re not going to use the developer straight away (it keeps for a few days), then don’t leave it in direct sunlight on a windowsill, and don’t shake it. The film has to be kept in the dark, which the development tank should do for you because of it’s design; don’t be tempted to open the tank up until you’re rinsing the film in water at the end of the entire process after the fix.


The Stop

To stop development, the instructions (rather confusingly listed under ‘Fixation’ at the bottom of the chart) say Ilfostop at a dilution of 1+19 for 10 seconds at 20 degrees. (I’ve highlighted this in yellow). You can rinse in water, but I’ve not tried it so can’t say what the results would be.

I use 300ml of stop.

This time there are 20 parts (1 + 19), so that’s 300ml/20 = 15ml per part. So that’s 285ml of water at 20 degrees and 15ml of Ilfostop.

The time for this is 10 seconds. Make a note of it. 

The Fix

I use Rapid Fixer. The instructions (under Fixation) say rapid fixer at a dilution of 1+4 for 2 – 5 minutes at 20 degrees. Again, I use 300ml of Rapid Fixer, so, although I’m sure that you’re now bored with the maths bit I’ll do it anyway…

1 + 4 means I need 5 parts, 1 fix and 4 water.

Each part will be 300ml/ 5 = 60ml

That’s (1 x 60ml) part of Rapid Fixer to (4 x 60ml) parts – i.e. 240ml of water.

Honestly, I don’t know what the difference is in fix times; I fix for 5 minutes. I tend to assume 5 minutes is best but 2 is okay if you’re in a rush. I have no evidence for this belief though!

Time 5 minutes. Make a note of it. 

The Rinse

When you finish the fix and pour it out you can open the tank to rinse the film in water; you don’t need to keep it dark at that point. I tend to leave it in the tank under running water at as close to 20 degrees as I can get for about ten minutes occasionally emptying it all out and letting it fill again.

If you’re using it, you only need a few drops of wetting solution. I tend to add a few drops at the end of the rinse with a pipette. By that time I have usually become impatient and removed part of the film from the reel to have a peek and see how it looks.

Don’t get hung up on the rinse temperature. It doesn’t have to be precise.

The time for this is about 5 to 10 minutes. 


I tend to measure out all of the chemicals I need as a first step which is why I’ve written this part, about preparing your chemicals, first.

I am not an expert and am not claiming to be. I’m primarily writing this as a guide/ reminder for myself; I’d developed film in the past and had forgotten how, so if it comes across as simple, that’s what I’m going for because I couldn’t find simple anywhere when I needed it!