How to Develop 35mm Color Film with Cinestill’s CS41 Kit

35mm Color Film Processing & Digitizing at Home

Processing your own film can be so rewarding for photographers. You save money, have more control over the look of your photos, and you no longer have to wait up to a week to get your film back from the lab. Plus, it feels great to go nearly completely analog!

There’s no better feeling than your rolls of film streamlining from camera, to tank, to hanging up in your bathroom after a great day of shooting- the instant satisfaction is just as great as shooting digitally.

This article will show you how to process & digitize your own film at home.

Here’s what you need to get started developing your own color film at home:

1. A darkroom or changing bag
2. Patterson Universal Developing Tank (this one has a 2-roll capacity)
3. CineStill Cs41 C-41 Color Negative Film Liquid Developing Kit
4. 3 Light-Tight Bottles for Your Chemicals- with Labels!
5. 3 Separate Funnels for Each Chemical
6. Sous Vide (I got mine on Facebook Marketplace for $15) or a simple thermometer
7. Bottle-Opener
8. Scissors
9. Timer (your phone works just fine)
10. Rubber Gloves
11. Access to water
12. Your Unprocessed 35mm Color Film
13. Scanner with Negative 35mm holder

If you’d rather watch than read about it, check out my 3-part TikTok series on My Process Developing & Digitizing 35mm Color Film below:

Step 1: Heat your Developers

After the initial mixing of your developer, blix (bleach-fix), & stabilizer (and pouring into their respective bottles), put the developer & blix chemical bottles into a container filled with water. A large bucket or old pot will do.

Place your sous-vide into the container, and let it heat to 102°F while you take the next steps to prepare your film for processing.

If you are using a thermometer, just make sure your temperature is 102°F before developing!

Step 2: Load your 35mm film onto the REELs of the Developing Tank

This part takes practice. Lots of practice.

Additionally, it needs to be done in complete darkness. So, you will either need a darkroom, or a light-proof changing bag! Personally, I have been using a changing bag since my apartment has so many windows!

Into the bag, or in the darkroom, you’ll include the following:

• Your 35mm film roll(s) to be processed
• Your developing tank
• Scissors/bottle-opener

Seal the bag shut, or turn off the lights.

Before starting, I like to throw on some music to make the process more relaxing. If you choose to do so, or are using a timer that is on your phone, make sure to keep it out of the changing bag/darkroom! Any light at all will ruin your negatives!

Now, you can get started. In the darkness or with your arms in the bag, carefully open the top of your 35mm film cannister(s) using the bottle-opener.

Note: If you’re in a pinch, and you find that your bottle-opener has the wrong type of opening for a film cannister, you can very carefully stick your fingertips in between the two felt lips of the opening alongside the cannister. Gently pull back the top layer as much as you can without hurting your fingers, and twist the nub at the top of the cannister until you can feel and extract the roll’s leader. I do not recommend this, as there is a slight risk of damaging your film/cutting your fingers on the metal if it rips. However, I have had to do this before when using the wrong type of bottle-opener, and my film came out perfectly fine.

Once your film is extracted to the point where you can locate your leader, trim it off so that the beginning of your roll is cut straight across.

After trimming the leader, open the developing tank and retrieve one of the reels. Run your thumbs along each side of the reel until you come across a notch on both sides. Line up the notches by twisting the reel, and hold it this way with one hand.

With the other hand, take the head of the 35mm film. Try to thread it between the two notches until you hear a faint ‘click’. Ever-so-slightly, tug the film to ensure that it’s hitched onto the small metal balls inside the notches.

When you’re sure the film has grabbed the reel, begin twisting each side of the reel back and forth to wind the film onto the reel. Once all of the film is wound around the reel, cut the tail of the film away from the spool inside the original cannister.

Place the reels back inside the development tank, and twist the inner funnel-shaped lid back into place until it clicks.

Step 3: Proccessing the 35mm Color film

The hard part’s over! You may now remove the materials from the changing bag, and then turn on the lights.

Head over to your developers, which should be at 102°F by now, and throw on some gloves to protect your hands from the harsh chemicals.

Follow CineStill’s Developing times in the chart provided with the chemicals, and use your timer for the following instructions:

Developing solution

1. Set your timer for 3.5 minutes, then pour the developer solution into the funnel-like lid of the developing tank. For the first 10 seconds, perform continuous inversion cycles or rotations. (Use the provided rotary drum OR put on the flat lid on that comes with the tank, ensuring that it is fully on and turn the tank upside down to right-side up continuously.) Repeat 4 of these motions every 30 seconds for the remainder of the 3.5 minutes.
2. After completing the steps above, pour the developer back into it’s container using the funnel designated to the developing solution.

Bleach Fix (Blix)

1. For 8 minutes, with the bleach fix (blix) repeat the same inversion/rotation process as outlined above (first 10 seconds, then 4 motions every 30 seconds).
2. Pour the blix back into it’s container using the funnel designated to this chemical.
3. Rinse out the blix solution from the tank by running water (75°F-105°F) over the tank for 3 minutes, OR by filling and emptying it with clean water 7 times to avoid contaminating the stabilizer.

Stabilizer

1. At room temperature, add the stabilizer for 30 seconds to 1 minute.
2. Pour the stabilizer back into it’s bottle, using the respective funnel.
3. Do not rinse out the stabilizer.

Step 4: Hang to dry overnight

Eventually, the film will dry and will then be ready to scan. You should now be able to see images on the negatives, as shown above.

Step 5: Scanning the negatives

For this step, you will need a scanner and a negative film holder for scanning your 35mm color film.

I use an Epson V600 Flatbed Scanner, which came with an attachment. However, you can find the negative holders for very cheap online. Once you have ahold of one, it is compatible with most scanners.

Now, you can cut your newly-processed negatives into sections of 6 frames each.

Place these sections into the negative holder, then research how to turn on 35mm scan settings on that particular scanner.

Voila! You have now both processed, as well as digitized your own film at home.

Although the first few attempts can be frustrating, once you get the hang of it, developing your own film can give you a deeper understanding of what goes into photography as a whole. The process can become almost meditative in nature, and gives photography artists a deeper appreciation for their own work.

You can check out the results I get by following this method of development here.