How To Develop Film at Home

If you’re a film photographer, and sick of spending tons of time and money getting your film developed by a lab, I’m happy to tell you that developing film at home is not too difficult and well worth learning how to do, especially if you shoot often. There will be a decent up front investment and you might mess up a roll or two, but in the long run it will save you time and money, give you the satisfaction of doing everything yourself, and allow you to have more control over the final look of your photos. Below I will give you my step, by step process for developing 120 color film at home. If you are developing 35mm film, everything will be the same except for the steps to load your film onto the film reel.

What You Will Need

Here are all the things you need to develop film at home. I will include links for some of these to products I have used and like, but you may be able to find alternatives or used equipment that works just as well.

• A room that can be completely pitch black OR a darkroom bag (LINK)

• Patterson Tank and film reel compatible with 120 film (LINK)

• C41 color film developing kit (LINK)

• Chemical Storage bottles (LINK)

• A Funnel

• A measuring cup that goes up to at least one liter

• A Sous Vide (LINK)

• A medium, water-tight bin

• A bottle of Photo-Flo (optional) (LINK)

• Metal chip clips or similar (LINK)

• A timer

• Wire clothes hanger

• Wooder kebob skewers (optional)

• Masking tape (optional)

Prepping Your Chemicals

First things first is chemical safety. Some of the chemicals you will be working with can be very harmful. Go slow, wear gloves, do not touch your face, eyes, mouth, etc. when handling these chemicals, make sure to wash your hands and equipment thoroughly after use, and work in an open space with air circulation.

For this process, there are three different chemical mixtures you’ll need to prepare before developing your film. You will not need to do this step every time, only when the chemicals need to be refreshed. I’ll get into when you’ll need to prepare new chemical mixes later in this blog. The three chemical mixes are the developer, the bleach and fix, which I will refer to as “blix”, and the stabilizer. These chemicals, especially the developer have a shelf life even if not being used so I recommend only preparing them once you are ready to develop your first roll of film.

The first thing to do is to label your chemical bottles. Write “DEV”, “BLIX”, and “STAB” on the lids so you do not mix them up. This is incredibly important since mixing these up will ruin your film. Your developer kit will come with preparation instructions so I will not get into specifics for that here. If your kit does not come with instructions be sure to look those up prior to mixing. Your kit should come with the correct amount of each component to make a given amount, so the water should be the only part that you’ll need to measure out. The process for preparation is essentially mixing components in a certain order, very simple. Note that the water must be heated to a specific temperature for each mixture. Your sous vide will allow you to bring the water up to the intended temperature.

Making your stabilizer mixture is super simple. This is an optional step in the process, but it really helps prevent things like water stains and artifacts on your film. You simply mix one part Photo-Flo with 200 parts water. I typically will use one liter of water and five milliliters of Photo-Flo. This is well worth the investment since with these ratios, a single bottle of Photo-Flo will last you essentially forever.

Film Developing Process

Once you have all of your chemicals prepared, you can begin the developing process. There are three different stages to the developing process. You’ll start by loading your Patterson Tank. This step is completed in the dark. Then you’ll do the actual chemical process of developing the film. Last, you’ll need to hang your film up to dry for a few hours. I’m going to break down each of these stages for you now.

Before anything, you should fill your bin with water, then use the sous vide to heat the water up to 102°F (39°C). Place your sealed developer bottle into the water to bring the developer mixture to that same temperature. Let this sit for a while so the temperatures can equalize.

While this is heating up, you can get going on loading your film into the Patterson Tank.

Loading Your Film

This part of the process needs to be done in complete darkness so you should make sure you have a good understanding of the steps to take and items you’ll need access to.

What You’ll Need

• Patterson Tank

• Roll of exposed film

• Film reel

• The cylinder that fits through the middle of the film reel

• The inner, plastic lid of the Patterson Tank.

• Darkroom bag (if you don’t have access to a dark room)

What you will be doing is loading your roll of film onto the reel, putting the reel and cylinder into the Patterson Tank, then putting the inner lid on the tank, all in the dark. Once this has been completed, you can turn the lights back on since the lid does not let any light into the tank. If you have a scrap piece of film to practice with in the light, that would be a great idea!

Your film reel may have two different sizes it can be positioned at. The shorter position is for 35mm film and the wider one is for 120 roll film. To adjust the size, twist one end of the reel counter-clockwise until the halves separate, position the halves of the reel into the wider state, then twist clockwise until it clicks back into place. Take a moment to familiarize yourself with the reel. You’ll notice a plastic spiral pattern on either end of the reel, your film will follow this spiral once loaded. On the outer edges of each end of the reel, you’ll see slots for the film to enter into and small metal balls just beyond that. This is the part of the reel you’ll need to be able to locate with your eyes closed, so take note of how it feels.

Place the cylinder through the reel and remember that the flat end of the cylinder needs to end up at the bottom of the tank. If you are doing this step in a dark room, place all of your items out neatly on a table. If you are using a dark room bag, put everything into the bag and try to keep things separated so they don’t get all mixed up.

In complete darkness, take the tape off of your exposed roll of film and begin to slowly unroll it. As you unroll, let the paper backing curl back onto itself so it stays organized and doesn’t go everywhere. Keep your fingernails pressed to the roll as you go, feeling for the beginning of the film. The film will feel much thicker and sturdier than the paper. Once you feel the beginning of the film, carefully roll out a couple of inches and give it a slight bend in the opposite direction that it was rolled up. This step will help the film go onto the reel easier. You will have a few inches of blank film before your first picture, so don't worry too much about touching the ends of the film.

While holding the end of your film, grab you reel and locate the slots on the edges of each side of the reel. Feed the film into the slots and pull it through until it catches onto the metal balls (Fig 1). The balls will hold onto the film so It doesn’t come back out. Once the film has been fed past the metal balls, you can carefully twist the ends of the reel back and forth and the film will continue to be fed onto the reel with each twist. Continue slowly until you reach the end of the film. Remove the piece of tape at the end of the film and continue rolling for a few more twists (Fig 2).

Once this is done, place the reel with the film on it into the Patterson tank with the flat end of the cylinder facing down. Put on the light seal lid and twist counter-clockwise until you feel it click into place. Congratulations, you have just loaded your film and can turn the lights back on or take everything out of the darkroom bag!

Fig 1

Fig 2

Developing Your Film

Now comes the part where you actually develop your film. As mentioned above, be sure to practice good chemical safety by wearing gloves, keeping the chemicals away from your eyes and mouth, and working in an open space with decent airflow. Ensure you have all the required elements ready to go before you start since these steps are time-sensitive.

What You’ll Need

• Bin full of water

• Sous-vide

• Developer mixture

• Blix mixture

• Stabilizer mixture

• Access to running warm water

• Patterson Tank with film pre-loaded

• Patterson Tank lid

• Agitator stick (comes with the Patterson Tank)

• Funnel

• Timer

Before beginning this stage, you should already have your developer mixture heated up to a temperature of 102°F (39°C) as described above. There are four different parts to this stage, the pre-rinse, the developer, the blix, and the stabilizer/final rinse.

To start with fill your tank about 3/4 full with your heated water. I typically go to the top of the hole in the inner lid of the Patterson Tank. Let this sit for one minute. When you pour out the water, there may be some discoloration to the water, don’t worry, that is normal. First part done!

The next part is the developer. Get a timer ready for three and a half minutes. Pour in your heated developer, again to about the top of the hole in the inner lid. Use the agitator stick to agitate for the first ten seconds. To do this, simply put the agitator stick into the hole in the inner lid and turn back and forth. You should feel this grab onto the plastic of the film reel cylinder and spin it back and forth. After ten seconds, quickly and carefully put the lid on the tank ensuring you get a complete seal all the way around.

Once the timer hits three minutes, pick up the tank and flip it over four times, rotating the tank one quarter turn after each flip. Briefly pause with the tank upside down each time to let the developer flow through the film to the top of the tank. Repeat this every 30 seconds until the timer reaches zero. You do not need to flip the tank at zero, so once you do you last set of flips at thirty seconds, you can start taking the lid off and preparing to put the developer back into its container using the funnel. Rinse off you funnel, tank lid, and agitator stick. If this isn’t the first roll that has been developed with this batch of developer, be sure to use the 2% rule (discussed below in the “chemical maintenance and storage” section”).

The next part is using your blix mixture, which should be at room temperature: 75°F (24°C) to 105°F (40°C). Get a timer ready for eight minutes. Pour in the same amount of blix mixture as you did developer. Use the agitator stick to agitate for the first ten seconds, put the lid on the tank ensuring a tight seal all the way around, then do the same four-flip cycles ever thirty seconds just as you did for the developer step. Once the timer hit zero, pour the blix back into its container.

Grab your stabilizer mixture and take your tank to a sink. At this point, your film is no longer light-sensitive so you can take the inner lid off of the tank. Rinse the tank out with warm, not hot, water for a couple minutes or until you’ve filled and emptied it around seven times. Lastly, pour in some stabilizer mixture and swirl it around for around a minute. Pour out the stabilizer mix, not back into its container, and you are done with the developing step! Last thing to do is hang your film up to dry.

Drying Your Film

The last step in the process is hanging your film to dry. My method for doing this is to put a metal clip on the bottom part of the wire clothes hanger. Then clip that to the top of your film. Then take 2-3 more clips all clipped to each other and attach them to the bottom of the film. This will weigh down your film so that it doesn’t curl up back onto itself.

Hang the film up somewhere that is room temperature and ensure it is not being blown around by a fan or open window. For the first ten to fifteen minutes I’d recommend keeping an eye on it to make sure it doesn’t start to curl up length-wise. If it does you can take some wooden kebob skewers to hold the film flat. place one skewer in the front and one in the back of the roll of film in a space between photo frames and tape them together. Do this as needed when you notice curling.

You’re all done! Now you just let your film dry for a few hours and you can scan or enlarge the negatives to digitize or make into prints! There are a few more general things to consider with developing your own film like chemical storage/maintenance and troubleshooting problems with I will get into below.

Chemical Maintenance and Storage

The chemical mixtures will not last forever. The developer especially will degrade over time and needs to be replaced occasionally. Some sources say your developer will only last 8-12 weeks, some say 6-8 months. The time your chemicals last will depend on your storage conditions and how often you use it. Here are some things that will help extend the life of your chemicals.

Store them in an opaque, dark container so that no light can get in. Use accordion bottles like the ones linked above so that when you store them, you can compress all of the air out of the containers. Air will cause the chemicals to degrade faster. Keep your chemicals stored at a consistent room temperature.

Your developer will also degrade as you use it. Most sources say you can confidently get at least 8 roll developed with a one quart kit, but many people easily get double or triple that number. You may see the quality start to degrade so just keep an eye out for that. To account for the degradation there is an important concept to remember called the “The 2% Rule”.

The 2% rule means for every roll of film you develop, you should add 2% developing time to your next roll of film. For example, if you have already developed four rolls of film with your developer, you should add 8% time to the developer stage on the 5th roll (about 17 seconds). At this point you would add a set of 4 flips when your timer hits three and a half minutes, then pour out the developer at three minutes and forty seven seconds.

Troubleshooting Problems

There’s not way around it, you are very likely going to mess up rolls at some point. I sure have. Here, I will list out a few common reasons for why you photos didn’t turn out right and ways to address the problem.

Your film strip came out completely blank

If your film strip is completely blank, no photos and no markings with the film stock and frame count along the edges, then something went wrong during the developing process. Your developer mixture may have gone bad and you need to prepare a new batch. You might have accidently put the blix in before the developer. If you see this, the first thing you should try is creating a new batch of chemicals and taking extra care to do everything in the right order for the next roll

All of the photos are blank, but the edges have the film stock information visible

If you can see the dark strips along the edges of your film containing information about what film stock was used and what the frame count is, then this means your developing process was a success, but something went wrong when capturing the photos. Check to see that the shutter on your camera isn’t stuck closed. Maybe your film wasn’t loaded into the camera properly and didn’t advance as you took photos. Maybe your photos were extremely underexposed. Regardless, to fix this, pay attention to properly loading your film into the camera, ensure all parts of the camera are functioning properly, and check your exposure.

All of your photos are completely black

If after you develop your roll, the entire thing is black, it means your film was exposed to light at some point. This could be that your photos were extremely overexposed, but more likely it means that at some point, your film got exposed to light when it was not meant to. Did you accidently open your camera back with the film still in it? Did you let some light in while loading your film onto the reel? You might also check that the light seal on your camera is intact. The fix for this is taking extra care with handling your film before it has been developed.

Your photos look cloudy, washed-out, and flat

Sometimes the lighting conditions when you photograph, can result in flat looking images. This is not what I’m talking about. If you captured images on a bright sunny day and are expecting lots of color, contrast, and punch, but are just getting… blah, this could indicate your developer has degraded significantly and it is time for a new batch. Try preparing new chemicals and giving it another go.

Have Fun!

Working with film is such a joy! It really adds to the experience to be able to do the whole process yourself. This may seem very complicated at first, but once you’ve developed a roll or two, you’ll see that’s its not too bad and well worth the effort. This is a learning process and you may mess some stuff up, but that’s ok. It is so satisfying to have a roll of film turn out beautifully and you’ll get much more control on how the photos look in the end versus just having a lab make all of the decisions for you.

The last part of the film process to think about doing yourself is the scanning. Let me know if you’d like to see a post about my tips for getting beautiful scans of your negatives.