Developing Colour Film as an Absolute Beginner

With CineStill Film Cs41 Powder Developing Kit

21 min read by Dmitri.
Published on . Updated on .

I’ve been shooting film for over a decade, yet I haven’t had the need to develop at home. The labs had always done a great job. Plus, I’ve been living in small apartments, travelled often, and didn’t mind spending money to save time.

Even when I began scanning film to get better results, home development was still neither an objective nor a necessity.

But, my monthly trips across town became more challenging after the new puppy arrived, forcing me to spend more time at the apartment.

Though it may sound like I am telling a story of being forced into developing film on my own, that isn’t the case at all. Instead, I like to think of home film development as a privilege with some responsibility, a lot of really cool science, and an avenue for creative expression. Which I was gently pushed towards by my life’s fortunate circumstances.

C-41, a beginner-friendly process.

I decided to start with C-41 (colour negative process) as that’s the kind of film I shoot the most. It’s also the least intimidating process.

The typical advice is to get started with black and white film as there’s no temperature control involved — presumably making it easier for beginners. But I’m not sure if that’s true in 2023:

Temperature control is easy with a plastic tub and a sous vide cooker. Whereas sifting through a wealth of non-standardized film development options for black and white film can be disorienting. All colour negative film, regardless of its ISO, has the same development temperature and time. Black and white film will have you look up Massive Dev Chart and pick from dozens of options for chemicals, timings, dilutions, etc.

However, there is an aspect of colour film development that requires particular attention — safety. The chemicals used in the C-41 process are corrosive and should be disposed of responsibly. Extra care is needed to avoid spillage and skin exposure. Still, the process is about as dangerous as pouring drain cleaner down a sink or cleaning with bleach.

CineStill Cs41 Colour Simplified powder concentrate developer.

Tools and chemicals.

Being an absolute beginner when it comes to home film development, I relied on advice from Daren (who blogs at Learn Film Photography). I’ve also gravitated towards CineStill products as they had the least intimidating packaging (a few powder packs looked easy enough, whereas a row of bottles of various sizes got my simple brain confused).

Two CineStill Film CS Collapsible Air Reduction Accordion Storage Bottles. To save some storage space and prolong the life of blix.

I’ll admit that the shopping list for all the stuff to develop film at home is quite long. The entire outfit cost me about $270. As of this writing, I used it to develop an equivalent of 9 rolls of 35mm/36exp. film, which would otherwise cost about $90 at a local lab.

At this point, I’m overpaying for my film development. But as I continue to develop it at home, I expect to pay around $30-40 for the same amount of film (maybe less as I experiment with extending development times as the chemicals become exhausted). Or about $3-5 per roll.

If you’re also planning to develop colour film at home, you’ll need to do some shopping. But at least you’ll know exactly what to get, which is:

🧪 CineStill Film Cs41 Powder Developing Kit for C-41 Color Film. This yields 1L of chemicals. Alternatively, you can get the chemicals in liquid form — they’ll have similar instructions, just more bottles.

Note: Some C-41 chemical kits come with a stabilizer bath. You can skip it unless you are developing film manufactured prior to the 1990s.

⚗️ Two CineStill Film CS Collapsible Air Reduction Accordion Storage Bottles (1000mL each). I like these bottles because they can be collapsed to take up less space and reduce oxygenation of the blix chemicals, i.e., prolong their shelf life.

⚗️ CineStill Film °Cs 1000mL Mixing Jug/Pitcher (though any plastic jug with 1000mL mark should do).

🌡 CineStill Film °Cs Temperature Control System TCS-1000. This tool is recommended because of the corrosion-resisting ceramic elements that make it safe to mix the chemicals by placing the tool into the liquid. Kitchen sous vide tools can work too, but I’d advise against sticking them in chemicals directly; instead, you’ll heat the water and mix with a stirrer rod. Never use any of the film development tools for food preparation.

⚗️ Paterson Super System 4 Universal Developing Tank and Reels. Fits nicely with the 1L chemical powder.

💡 Sensei Large Changing Bag. Fits everything that needs to fit into ready film reels in complete darkness.

📩 Print File 35mm Archival Storage Pages for Negatives. I scan and archive my film at home. You’ll still need a way to store yours if you’re planning to hand it to your local lab or a friend for digitization or printing.

🧼 Paterson Film Squeegee. This is essential for getting rid of water spots on your negatives. If you’re planning to develop medium format film only, this won’t work — you may want to use a lint-free cloth instead.

🔨 Samigon Pro Film Retriever. This tool lets you extract film leader from 35mm film canisters which can then be upcycled. If you’re planning to develop medium format film only, this is not necessary.

🛁 A large plastic tub. I use it to heat water to 38℃ and keep the chemicals at that temperature as they float in their jugs inside that tub.

🌡 A kitchen thermometer to verify that the chemicals inside the bottles reached the correct temperature.

🧦 Hanging pins to dry the film.

✏️ Masking tape and a marker to clearly label the chemicals.

🧤​ Rubber or latex gloves and a lab coat. I didn’t use them, but they are recommended: blix can burn skin and mess up your clothes.

Working space.

To develop film at home, you’ll need a sink, running water, a plug for your sous vide/TCS-1000, and some surface to place all your stuff on. It’s also good to have a trash can and a roll of paper towels handy to clean up any spillage. Most bathrooms should do the job (you may want to “book” yours for two hours to make sure you aren’t interrupting anyone’s shower time and ensure you’re able to yield the space when needed).

Before mixing your chemicals: if you’re using sous vide, you’ll need a tub of warm water. You’ll need to fill it so that the water level is between the “min” and “max” markings on the device. You’ll be using slightly more than 2L of water heated to 38℃/100℉.

Mixing blix chemicals with CineStill Film °Cs Temperature Control System TCS-1000.

Mixing the chemicals.

The first thing to do is to mix the powder. This needs to be done just once and repeated only when you get new chems after the old ones expire. Here’s how to check if your chemicals have expired.

Note: A reader has suggested that it’s important to wear a mask while mixing powdered chemicals.

CineStill Cs41 Colour Simplified powder concentrate kit comes in three pouches with an indefinite* shelf life (before mixing). They need to be mixed with water into two solutions: the developer, which should last 2-6 weeks*, and the blix mixture, which should last 8-12 weeks*.

Powder chemicals should be mixed at around 38℃/100℉.

✱ — The lack of definitive expiration times, according to CineStill, is due to their inability to predict the storage conditions and contamination rate of the chemicals. This includes contact with oxygen, temperature, number of rolls developed, etc. So far, I’ve been able to push a few days past the safest estimates with no issues.

👉 C-41 chemicals need to be mixed at 38℃/100℉. You can do that with CineStill TCS-1000 — as long as you rinse it well before placing it into the blix solution. If you’ve got a kitchen sous vide, avoid placing it into chemicals. Instead, use it to heat the water for powder dilution and use a stirring stick to mix everything well.

Here’s how the process went for me:

Mixing colour developer. Following the instructions sheet, I heated 600mL of water in a plastic pitcher and began adding the colour developer powder while mixing until no crystals or sediments remained.

Once everything looked homogenous, I topped up the pitcher with warm water to 1L, mixed some more and poured the solution into a storage (collapsable) bottle. It’s important to label it to ensure no ruinous mistakes during film development — as I was told (it’s good advice).

The developer bottle is lablelled with “D” on the cap and the bottle (to avoid any mix-up). The blix bottle is labelled accordingly, with “BX.”

Mixing the blix solution. Following the instructions sheet, I heated 600mL of water in a clean plastic pitcher and began adding the blix “Part A” powder while mixing until no crystals or sediments remained. Once everything looked homogenous, I poured the solution into the second clean storage bottle.

The next step is adding the powder from the packet marked “Part B” into the storage bottle with the “Part A” solution. This created an endothermic reaction, heating the bottle slightly during the next five minutes.

As the solution heated slightly, I poured it back and forth between the storage bottle and the plastic pitcher. Then, once it looked homogenous and no crystals or sediments remained, I poured it one last time into the pitcher and topped it off with warm water to 1L. Finally, the blix solution went into the storage bottle; I carefully squeezed it and sealed it so that there was very little air left inside.

CineStill Cs41 Colour Simplified powder concentrate kit.

Loading 35mm film into Paterson reels.

Now that the chemicals are ready, the development may begin. Loading film into a light-tight Paterson tank makes developing film possible without a darkroom; however, it’s a time-consuming process.

To get things moving, I filled the large plastic tub with water above the min and below the max markings of the sous vide/TCS-1000 (or about halfway/~3gal/~10L) and set the temperature to 39℃/102℉. I then placed my two bottles with tightly closed caps into the water.

Note: I cover loading medium format film in the next chapter.

A large plastic tub with bottles of mixed C-41 chemicals is getting warmed up for film development.

Extracting film leader from a 35mm film canister is annoying at first. I do it because I don’t want to destroy perfectly good canisters for bulk loading. Also, I find it easier to load film onto Paterson reels when it’s fed gradually from the canister instead of coiling all over the place inside the dark bag. The good news is that this gets easier with time — either the retriever gets broken in or a muscle memory kicks in.

Watch a short video of how to retrieve film from 35mm canisters.

Samigon Pro Film Retriever

Film retrievers typically have three flexible plastic blades with curved tips that all need to be inserted into the canister at once.

You then need to rotate the core of the 35mm film canister (the part that sticks out) in a counter-clockwise direction a few times. As you do that, listen for soft clicks as the leader top passes the film retriever blades; after you’ve heard one or two clicks, you can push the first plastic blade further into the can — then repeat the clicks. Then again, with the second blade. And finally: pull the film retriever in a swift (but not jerky) motion.

Chances are this will not work on the first try. It takes me 2-3 tries; some people can do it right away — it’s an experience thing.

With the film leader finally out, you’ll need to cut the tip so that it’s flat. It helps to round the edges slightly so that it’s easier to feed into the reels.

To simplify the process further, I pull about 5” of the film out of the canister and feed it into the Paterson tank reel in daylight. This is about the same amount you need to have out for loading the film into the camera; thus, there should be no photos on it.

Prepping film before loading into Paterson tank reels inside a changing bag. Note the plastic wedges, underneath the film should be fed and the amount of film that goes into each reel.

The top and bottom parts of each reel can turn a few degrees independently. To get the film into the reel, they should be turned so that the two little wedges that face inwards on the top and bottom parts of the reel line up. See the photos in this article for further guidance.

Once the wedges are lined-up, the film should be fed just underneath them, along the wheel, past the bearings that are about 1.5” away from the wedges. This should fix the film in-position sufficiently for careful handling without falling out.

With the film pre-loaded into the reels, it’s time to get the Ptterson tank (which includes the funnel-lid and a plastic core that needs to be inserted into the reels) and scissors ready to go into the changing bag along with the film. My Sensei bag lists some unhealthy components, so I ensured not to use it on my dining table. Before placing everything inside, I arranged my scissors, reel core and the tank neatly so that I could remember where things are without being able to see.

Naturally, everything goes inside the changing bag, which needs to be zipped up shut so no light enters, and the arms go into the sleeves to do the bulk of the work:

Getting 35mm film pre-loaded into Paterson reels before feeding the rest inside the changing bag.

Having made a few mistakes, I’ve learned to go slow once the film is in the bag. The process involves turning the Paterson reels slightly back and forth, which feeds the film inwards mechanically. Doing this too fast or with too much force can cause issues which are hard to fix inside the changing bag.

The process may feel like there’s some resistance at times, and the film may sound as if it’s crumpling. My approach in those cases is to proceed with caution until all of the film is inside the reel and turning the reels feels fee-er.

The advantage of feeding the film into reels from an in-tact canister is that you can pull out about five inches of it at a time and turn the reels in the air as the canister elevates upwards. It will then reach your fingers, which is easy to identify, and then pull a bit more film out. As I turn the reels in the dark bag, I find it helpful to keep my thumbs on the wedges (right where the film enters the reel); that way, I can feel if there are any issues.

Paterson Film Squeegee. To get the water spots off the negatives.

I’ve also learned that fingerprints are usually not an issue as you load undeveloped film into the reels. Mine did not show up on the scans, despite the awkward fumbling as a first-time chemist. But they will show up on scans if you happen to leave some after the roll is developed.

36exp./35mm film feels a little longer than expected inside the changing bag. Once the end is reached (at last), I leave about two fingers’ worth of film on the canister and snip it carefully with scissors; the final piece of the puzzle is to rock the remainder of the film into the reel until the wheels start turning easier.

With the first roll of film on the reel, the core goes into the reel (it doesn’t matter which way) and into the tank. The second reel should also go onto the core if you’re developing just one roll or with your second roll. The funnel-lid goes on top. You want to twist the lid closed until it clicks. Double-checking that the lid is secure can be done by flipping the Paterson tank upside down inside the changing bag: the lid should stay on.

Now it’s safe to take the Paterson tank out of the changing bag and into the bathroom, where the chemicals should be warm and ready to go.

Loading medium format film into Paterson reels.

There are a lot of similarities between 35mm and medium format film loading. However, there are some key differences:

You’ll need to adjust your Paterson reels to fit the film — you can do this by twisting them counter-clockwise to unlock then extend and lock by twisting in the opposite direction.

120 film can’t be pre-loaded into the reels, so you’ll need to do everything inside a dark bag. As with 35mm film, you’ll need your tank, tank funnel-lid, reel(s), tank core, and scissors inside the bag.

Start by gently unwinding the film while running your fingers down the strip until you feel the emulsion. You’ll want to separate it from the paper. Optionally, cut small bits of the corners (in the dark) to possibly help yourself with fitting the film inside the reel(s). This is the difficult part: medium format film is larger and thus more flexible and harder to fit in the reels, so take your time and try not to get too frustrated. It’s OK to take a break.

Puring in developer and timing agitations.

Processing colour film in C-41 chemicals.

Compared to all the prep so far, developing film in C-41 chemicals is the easy part. Once the developer is poured into the Paterson tank, the film can be hung to dry within 12 minutes.

There are two steps: 1) develop for 3.5min at 39℃/102℉ and 2) bleach & fix for 8min (6 min if you use liquid chemicals, or follow the instructions on your package).

Both steps require agitation — a technique of inverting and rotating the Paterson tank so that the chemicals move around inside. This should be done in a gentle continuous motion as you hold each end of the tank without letting go. Initial agitation (after either pouring the developer or blix into the tank) should last about 10 seconds, after which you want to do four inversion cycles (or a complete cycle of flipping the tank upside down and then upwards).

Having developed a few dozen rolls using the inversion technique, I switched to using a stirrer stick with a combination of tapping the tank after each set of four rotations in alternating directions. It feels less physical, and there are fewer chances of spilling the chemicals that way.

I’ve also learned that while important, timing the steps does not have to be perfect. A few seconds off will not ruin the film.

Tapping the tank on the counter rids the mix of the bubbles. Burping your Paterson tank: once you pour warm chemicals into the tank and seal them with the flexible lid, they will expand — especially blix — which will cause leakage and problems. To prevent that, push as much air as possible out of the tank by lifting one side of the flexible lid slightly and pushing the middle part of it in. This is the part you’d want to do with the gloves on, as some chemicals may spit out in the process. I also double-check to ensure the flexible lid is closed tight, as cleaning spilled blix is no fun. Burping is not needed if you’re using a stirring rod.

And finally: the amount of chemicals that should go into the tank. I’ve had great results by pouring enough to see a small pool form on top of the funnel — but not to the rim, as that makes agitation difficult.

The chemical steps. Pour in the developer (you may want to double-check its temperature with a kitchen thermometer beforehand). Agitate for 10 min, then four inversions every 30 seconds. I used a timer set for 3 minutes and 30 seconds and watched the seconds hit the half-mark to pick up the tank and do the inversions until the timer rang.

The developer needs to be 39℃/102℉ while it’s in the tank. You don’t need to dip the tank into your warm water pool between agitations; it’ll retain the heat sufficiently for three minutes (unless it’s cold in your space; heat the chemicals one degree higher to compensate). The bleach and the optional pre-soak with water don’t need to be 39℃, but I figured it helps to keep everything consistent to avoid reticulation.

Once done with the developer, it should be poured back into its bottle, sealed and put aside. It helps to fill the Paterson tank with warm water and empty it before moving on to the blix step. Doing so reduces bleach contamination.

The blix step is identical to the dev step, with the exception of being sustained for 8 minutes instead of 3.5. Once done, the blix solution should be poured back into the bottle and sealed.

The last step is to wash the film, which is convenient as there’s a tub full of water used to heat the chemicals that shouldn’t just be wasted. I use all of that to cycle through the Paterson tank.

Drying, scanning, and archiving developed colour film.

Unwinding film from the Paterson reel feels a little strange at first. In my case, pulling on the leader did not release it smoothly. Instead, I peeled the film from the reel, forcing it to curl a little (I held the reel with my thumb and index finger pressing down on the sides of its core); as I did that, the reel eventually gave and began rotating as the strip slid out. I had to keep my arm holding the reel stretched high up so that the bottom part of the film would not touch the floor. I’m 5’9”.

Noodle and Norah on Kodak Gold 200. Developed in CineStill Film Cs41 Powder Developing Kit for C-41 Color Film.

I hung my film on clothing pins; however, to use my Paterson Film Squeegee, I had to hold the top part with my fingers as clothing pins aren’t strong enough to grip it as the squeegee screeches down, collecting the water on the way. I later asked my brother to 3D-print a simple design that relied on perforations to keep my film secure as I scrubbed it dry.

✪​ Note: The squeegee needs to brush all the water from the film’s surface so that the remaining droplets do not dry and show up on film as rings. I do this rather forcefully (photographic film is resilient), sometimes twice. But it is somewhat of an optional step as distilled water is less likely to form rings — and you can do this step after the film is dry to fix those rings (you’ll need to wet the film and then squeegee it).

This is not all, of course. After about an hour of drying in the bathroom, I scanned my film into digital negatives, created inverted copies using the histogram equalization method, and sleeved the physical masters.

Your scanning methods may vary, but the negatives should look the same as when you receive them from the lab. I’ve learned that common problems include streaks of colours “leaking” down film perforations, images that look too thin or too dense, and various imperfections that blow up on a scan.

 ☝︎Further reading:How to Store & Organize Film & Film Scans” — useful advice for digital and physical film archival techniques.

Storing tools and chemicals.

My plastic tub fits everything in nicely. But before closing its lid, I made sure that all my tools that were in contact with the chemicals were rinsed; with everything inside the box, I left it open for a few hours to ensure everything was dry. Loading film onto wet reels is nearly impossible, apparently.

Safe disposal.

Once the chemicals are spent, they must be taken to a disposal facility — especially the blix solution. That’s often the lab or a local disposal facility, which may charge you a small fee.