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Developing with Bellini C-41 Kit
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Developing Film at Home with the Bellini C-41 Kit
Developing your own colour film at home is one of the most satisfying things you can do as a film photographer. This guide walks you through the whole process using the Bellini C-41 Kit, step by step.
Before You Start
If you have never developed film before, the idea of working with chemicals and hitting exact temperatures might feel a bit daunting. That is completely normal. The good news is that C-41 (the process used for standard colour negative film) is actually very well suited to home development. The steps are straightforward, the chemistry is consistent, and once you have done it a couple of times it becomes second nature.
The Bellini C-41 Kit is made by Bellini Foto, an Italian photographic chemistry company with decades of experience formulating film chemicals. The kit is designed for the C-41 RA (Rapid Access) process at 38 °C and contains everything you need to go from an exposed roll of film to a developed negative. Bellini uses a single-part developer concentrate, which makes mixing simpler than two-part alternatives. The chemistry is known in the film community for being reliable and consistent batch after batch.
The process runs through four chemical baths: developer, bleach, fixer, and stabilizer. Each one does a specific job. The developer brings out the latent image in your film. The bleach converts the silver in the image to a form the fixer can remove. The fixer clears away the remaining silver, making the image permanent. The stabilizer protects the finished negative and helps it dry cleanly. You just need to take each step in order and keep an eye on your timing and temperature.
If you have an AGO Film Processor, the process becomes even more approachable. The AGO tracks the temperature of your chemistry throughout development and automatically adjusts the timing to compensate, so you always get accurate results without having to manage a water bath or watch a thermometer.
What You'll Need
Before you mix any chemistry, gather everything on this list. Having it all within reach before you start makes the process much smoother.
- Bellini C-41 Kit (Developer concentrate, Bleach-RA, Fixer-RA, Stabilizer concentrate)
- Film developing tank and reels (e.g. Paterson or similar)
- Measuring jugs and mixing bottles (preferably amber to protect chemistry from light)
- Accurate thermometer (for 38 °C / 100 °F control)
- Timer or stopwatch
- Protective gloves and safety goggles
- Scissors
- Light-tight changing bag (or access to a darkroom) for loading the film
- Drying clips
Optional but highly recommended: The AGO Film Processor monitors your chemistry temperature and adjusts development timing automatically, so you always get accurate results without babysitting a water bath.
About the Bellini C-41 Kit
Each kit contains concentrates that mix into the following working-solution volumes:
| Chemical | Volume | Note |
|---|---|---|
| Developer | 1 L | working solution |
| Bleach-RA | 1 L | ready to use, no dilution needed |
| Fixer-RA | 1 L | working solution |
| Stabilizer | 10 L | working solution |
Kit capacity: 12 rolls of 36-exp 35 mm · 12 rolls of 120 medium format · 44 sheets of 4×5″ large format film.
When using the AGO Film Processor, its rotational agitation uses less chemistry than manual inversion, which means you may get more rolls out of a single kit than the standard figures above.
Mixing the Chemistry
Mix your chemicals fresh before your first session. It only takes a few minutes. One important rule: always add concentrate to water, never pour water into concentrate. This prevents unwanted reactions when mixing.
1 - Developer
740 ml water + 260 ml concentrate → 1 L working solution.
2 - Bleach-RA
Supplied ready-to-use. No mixing needed, just pour it into your storage bottle.
3 - Fixer-RA
500 ml water + 500 ml concentrate → 1 L working solution.
4 - Stabilizer
990 ml water + 10 ml concentrate → 1 L working solution. The kit makes up to 10 L total, so mix only what you need.
Step-by-Step Developing Process
The times below are for use with the AGO Film Processor. If you are developing manually, refer to the process summary table further down for times adjusted by roll count.
Step 1 Pre-Warm: 38 °C, 3:00 min
Place your loaded developing tank into a water bath that is slightly above 38 °C. This brings the film itself up to the right temperature before chemistry touches it. This is a dry step, so keep the tank sealed and make sure no water gets inside during pre-heating.
Step 2 Developer: 38 °C, 3:15 min
This is the most important step. The developer reacts with the exposed silver in your film to create the visible image. Temperature accuracy here really matters, as even a degree or two off will affect your results. The AGO Film Processor tracks this for you and adjusts timing accordingly.
If developing manually, the time increases slightly with each batch as the chemistry gradually exhausts:
- Rolls 1-3: 3:15 min
- Rolls 4-6: 3:30 min
- Rolls 7-9: 3:45 min
- Rolls 10-12: 4:00 min
Agitation (manual): 15 sec continuous inversions at the start, then 5 sec every 30 sec.
Step 3 Bleach-RA: 32-38 °C, 0:45 min
The bleach converts the metallic silver that the developer created into a form that the fixer can remove. Without this step your negatives would come out very dark. Agitate continuously throughout.
Step 4 Fixer-RA: 32-38 °C, 1:30 min
The fixer removes all the remaining light-sensitive silver from your film, making the image stable and permanent. After this step your film is no longer light-sensitive and can be handled in normal light. Agitate continuously throughout.
Step 5 Stabilizer: 32-38 °C, 3:00 min
The stabilizer protects the dyes in your negatives and helps the film dry without water marks. Agitate continuously. After fixing you have two options for how to use it:
- Option A: Rinse with running water first, then do one final rinse with diluted stabilizer.
- Option B: Skip the water rinse entirely and do 3-4 stabilizer rinses of 45 sec to 1 min each.
⚠ If using Option B, do not rinse with water before stabilizer
Process Summary
A quick reference for all steps. Bookmark this page so you can check it during development.
| Step | Temp (°C) | AGO Time | Manual Time * | Agitation |
|---|---|---|---|---|
| Pre-Warm | ~38 | 3:00 min | 3:00 min | Dry, no water in tank |
| Developer | 38 ± 0.2 | 3:15 min | 3:15-4:00 min * | 15 s continuous, then 5 s / 30 s |
| Bleach-RA | 32-38 | 0:45 min | 0:45-1:00 min | Continuous |
| Fixer-RA | 32-38 | 1:30 min | 1:30-2:00 min | Continuous |
| Stabilizer | 32-38 | 3:00 min | 3:00 min | Continuous |
* Manual developer time: rolls 1-3 at 3:15, rolls 4-6 at 3:30, rolls 7-9 at 3:45, rolls 10-12 at 4:00.
Tips for Better Results
- Temperature is the most important variable in C-41. Keep developer at a steady 38 °C as even small shifts will affect your results.
- If developing without a thermostatic bath, you can compensate by starting slightly higher: 42-43 °C when room temperature is below 20 °C, or 41-42 °C when room temperature is above 20 °C.
- The AGO Film Processor monitors your chemistry temperature throughout development and adjusts timing automatically, removing the guesswork entirely.
- The AGO uses rotational (horizontal) agitation, which requires less chemistry to cover the film than manual inversion. This means you will likely get more rolls out of a kit than the standard capacity figures suggest.
- Developer exhausts faster than the other chemicals. Bellini sells the developer separately for this reason, as bleach, fixer, and stabilizer will often last twice as long, so you can top up just the developer without replacing the full kit.
- The stabilizer capacity is very generous at 10 L per kit. You may notice a small amount of residue settling at the bottom of the bottle over time. This is normal and does not affect performance.
- When mixing, always add concentrate to water. Never add water to concentrate.
Chemistry Shelf Life
Once you open your chemistry, oxidation gradually starts to break it down. These guidelines help you get the most out of each kit. As a general rule, try to develop as close to the full kit capacity as possible in one session rather than spreading rolls out over many weeks.
- Working solution left open: 3 days
- Working solution in a sealed bottle: 2 weeks
- Opened concentrate in a sealed bottle (squeeze out the air first): 4 weeks
- Unopened concentrate (always check for signs of oxidation before use): 1-1.5 years
Your First Roll Is Closer Than You Think
Developing your own colour film is a genuinely rewarding experience. There is something quite special about pulling a freshly developed roll from the tank and holding your negatives up to the light for the first time, knowing you did that yourself.
The Bellini C-41 Kit makes it accessible. The chemistry is reliable, the instructions are clear, and the process is consistent enough that even your first attempt is likely to go well. Once you have done it once, the whole thing takes less than 15 minutes of active time from first step to finished negative.
If you have any questions about the process, the chemistry, or getting started with the AGO Film Processor, feel free to reach out to us. We are always happy to help you get your first roll developed.
Updated on 13 Feb 2026