Tutorial: Home made C-41 development at room temperature

In this tutorial I will show how to develop your c-41 colour film at home at room temperature.

I decided to write this tutorial, because it still is widely believed, that it is extremely difficult to develop colour film because it is so important to keep the temperature at exactly 37.8 °C when developing color film and that a little drift of maybe 0.5 °C will lead to weird colour curves and shifts which are never able to be corrected afterwards.

Because of this misinformation it was believed for decades, that without some expensive machinery home developing of colour film is just impossible.

Luckily the change of information flow through the introduction of the internet changed this and made it possible to spread the idea of developing C-41 at room temperature.

So forget about these scare tactics, you don’t need an expensive colour processor, special thermometers or a three year apprenticeship but can do home developing of C-41 at home just as easy as you do your black and white film development.

The great thing is, that you can even do different developing technics, like stand development, experiment with different agitation schemes and do push and pull development. There are even methods to extremely push C41 to EI 25.600, but this is a different thing I will explain in another blog entry – to be honest I have to try it out by myself first.

And if you you think, that you need a dark room to be able to develop film at home, I can tell you, that most press photographs in the past were able to develop their films on their hotel rooms, either by using a light tight changing bag, or at night in an unlit room under a thick bedcover.

I will start right at the beginning, so even if you never developed any film before, you will understand how to do it after reading the tutorial.

Preparing the film

So at first we start with the exposed film. It is best to not rewind your film entirely when it is fully exposed, so that the last few centimetres still are outside the film canister. If you manually rewind the film you feel, when it is released from the winding reel and stop winding. If you work with a camera that automatically rewinds, there sometimes is a setting to leave the last part of the film outside.

If this did not work correctly, there are two ways, to get the film back out. The simpler way is to open the can with a bottle opener inside the dark room or your changing bag. Another convenient toll is a film picker. You can slide it inside the can and pull out the film with it.

Pulling film out of the film canister using a film picker.
If you don’t have a film picker you can use a bottle opener as well

The next step is to cut the end of the film straight with little cut offs at the edges, so that the film can be easily wound onto a film spool.

So the next step is to wind the film on the developing reel. This of course has to happen in the dark, I only took a picture to illustrate how it works.

Winding the film on the reel – do this in the dark please.
A changing bag is a convenient tool to work in the dark without the need to set up a dark room. Is is made from thick and lighttight fabric, has a zipper and a folded edge and finally two openings to reach with the hands inside.

Mixing the developer

Enclosed to your developing agents there comes a description on how to mix the chemicals. You can follow these instructions or try out the one shot developer I’ll describe later on.

It is recommended to use distilled water to mix the developer, fixer, bleach and stabilisers. To keep things simple I would advice you to try it with tap water at first. If you get clean negatives without stains on them after drying you can use the tap water.

I always used tap water, only after I moved to another city, I had to use distilled water, because the tap water here is extremely hard.

Another way is to wipe the stains of with ethyl alcohol after drying the negatives.

Developing Times – Standard Developer

Standard developing times for the C41 process is 3¼ minutes at 38°C.
Most C41 Kits also give times for 45°C (2 min.) and 25°C (13 min.) some even for 20°C (21 min.)

Pipette inside a measure cylinder. Both besides a bottle of part C developing agent.
It can be helpful to use a pipette to mix the one shot developer. Also a measuring cylinder is needed to keep the three ingredients in their proper balance.

One shot developer – special mixture

I like to use a one shot developer, because it has some advantages over the standard developer. At first, if you do not develop films very often, you do not have to be afraid that your developer is exhaused because of oxidation. If you mix the developers ingredients together they spoil way faster than if you only open the bottles and take out exactly the amount you need.

The drawbacks are, that you need to measure the three developer’s ingredients very exactly or you could produce rather strong colour shifts. Also you will produce a thinner developing solution so the developing times will be longer.

So here are my recipes (actually they are not mine, I got them from a forums threath – look at the links section at the bottom).

One shot developer made of Rollei Colorchem C-41 developer:

  • 240 ml water
  • 5 ml part A
  • 2,5 ml part B
  • 2,5 ml part C

If you use the Digibase C41 chemicals (same for Fuji Hunt, since it seems to be exactly the same kit):

  • ca. 235 ml water
  • 2,5 ml part A
  • 2,5 ml part B
  • 2,5 ml part C
  • 0.5 ml starter

I’ve never tried it with the Tetenal kit but if you have the numbers for 5 liters of developer just divide the ingredients by 100. This should work since the C41 process is very tightly standardised and 5 l of developer should last for 100 films.

Exception: If you use 400 ISO film or faster, you could try to use up to the double amount of developing ingredients, since high speed films just tend to need more developer.


Developing Times – One Shot Developer

I calculated some time-temperature combinations that worked fine for me:

  • 11 minutes at 30°C
  • 21 minutes at 24°C
  • 22 minutes at 23°C
  • 24 minutes at 22°C
  • 30 minutes at 20°C
  • 33 minutes at 19°C (yes, it gets that cold where I live)

That all was derived from the given combination of 5½ minutes at 38°C.

A thermometer that was made for black and white development is absolutely sufficient for developing colour film at room temperature.

Anyway, it is better to rather keep it a bit longer inside the developer than shorter. Since there is only a limited amount of developer inside the dilution, the film will probably exhaust the developing agents anyway, so there will be only a marginal further chemical reaction take place if the film is kept inside the developer any longer.

Also you should not go below 18°C because some agents of the developer could come to an halt here.

If possible, you should keep the developing temperature at 25°C or higher, because the grain will become bigger with lower temperatures.

Agitation Scheme

If you send your film to a professional lab for developing, it will not be spooled inside a reel but rather run through different developing, fixing, bleaching and washing baths, until it comes out  dry and flat at the other end of the machine. This means that there will be a constantl flow of fresh chemistry passing the film.

To simulate this, home developing processors attach the developing drums to a motor and make them rotate inside a warm water bath. So the drum will rotate constantly, ideally changing directions constantly.

Still this agitation scheme is not ideal, because the part of the film that is further away from the axis of rotation moves with a different speed through the developer, than that part that is located at the center. So there are some people who measured out, that there are differences in the development between end and beginning of the film stripe.

So, even without being stingy you can say, that you do without a processor for a more even development. Therefore it is said that the most even development comes from tanks that are gently tilted every then and when.

But when you think tilting and tilting is all the same will soon be mistaken. Because even how quick, how long and how often you agitate the developing tank has an impact on the quality and look of the final image.

The more and the stronger you agitate the larger the film grain will be, thus leading to a lower resolution but also a sharper look. Also the film will be able to resolve a smaller difference between the darkest and the brightest part of the picture if it is agitated more often – you say the developing curve gets steeper or that the film has a smaller dynamic range or contrast range.

So there are two poles in this context:

  • larger grain (less resolution)
  • sharper look
  • increased agitation
  • stronger concentrated developer
  • smaller dynamic range (difference between brightest and darkest area in the picture)
  • shorter developing time


  • smaller grain (higher resolution)
  • softer look
  • less agitation
  • higher diluted developer
  • larger dynamic range
  • longer developing time

Independently from this a lower temperature will produce larger grain, that is why it is recomended not to work with temperatures below 25°C.

So one can see, that if we use the high diluted one shot developer the picture should become less grainy than the developer in the standard process and also will be capable to reproduce a few stops more of dynamic range.

The problem is, that if we dilute higher, we need to develop longer, which means we have to develop at room temperature or have to take into account that the temperature will drop during development.

But, by developing at higher dilution and less agitation we can compensate the high grain a lot.

So practically there are the following common agitation schemes:

  1. Stand development: A very high diluted developer will be used, the amount of developer will exhaust during development. Initially there will be a continuous agitation for one minute or 30 second. For the rest of the time (normally between 60 and 120 minutes) the tank will stand still.
    What happens is, that the lights will become less developed than the shadows because here the developer close to the emulsion will exhaust sooner and because of lacking agitation fresh developer will need longer to arrive in these areas.
    Also this will enhance contrast where very bright areas adjoin dark areas, since the bright ares “steel” the developer from the dark areas, making them become even darker.
  2. Semi stand development: more or less the same as stand development with the difference that there is only marginal agitation. For example the tank is tilted once every 20 or 40 minutes very slow and gently. Developing times do not really differ from stand development.
  3. Normal tank development. Agitate for the first 30 or 60 seconds continuously and then once every 30 seconds or for 10 seconds (three tilts) every minute.
  4. A declining agitation that takes into account the growing dilution of the developer during development: initially only for 30 seconds and then very gently one tilt every 30 second. In the last third of the developing time the agitation is reduced to only one tilt every minute. If the time exceeds 25 minutes, agitation will be reduced to once every 5 minutes from this point on.

All these different schemes have an impact on the developing time. This is obvious since more agitation speeds up the chemical process. So most developing times are given for rotation and scheme 3 (normal tank development). Some give different times for rotation and hand inversion while expanding developing times by the factor 1.3 in hand inversion. Kodak for example gives different times for small tanks (1 or two rolls) vs. large tanks.

As a conclusion you see, that there are a lot of factors that have an influence on the results – and these differences are really noticeable in the picture’s appearance.

My advice would be to start with a simple agitation scheme like number 3 (normal tank development) and when you are familiar with it you start to experiment with different schemes. But take care not to read too much about it on the internet – one could get lost for hours reading about this stuff, instead of developing a couple of films making one’s own experiences.

Links  – Sources and further reading




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