Interpreting the Fuji Hunt C41 instructions

One of my most popular posts, according to my WordPress stats, was one I wrote in 2015 which reprinted a legible version of the instructions for the Fuji Hunt X-press C41 developing kit. 

A few readers have asked for more explanation of one table in the instructions – this one below:table3

So I’ll try to put in into words and see if I can make it clear. First, I’ve actually amended the title of the last column to make it clear that this table would apply if you made up all of the chemicals it once, to give you 5 litres of solution. Unless you’re processing film commercially, or you shoot an awful lot of C41 film in a short space of time, this might be unlikely and the instructions will have to be amended for a smaller amount of chemicals. But I’ll come to that a bit later …

So we’ll start off by just looking at the first data row in the table, which applies if you are developing ISO100 film in 120 format. The last column tells us that the most films which Fuji think you can develop with 5 litres, is 120 films.

  • When you develop the first 16 films with this 5 litre batch of chemicals, you would use the processing time 3’15” (3 minutes and 15 seconds).
  • When you develop the NEXT 16 films with the same 5 litre batch of chemicals, then you increase the processing time to compensate for the partial exhaustion of the chemicals. The new processing time is 3’18”
  • When you develop the NEXT 16 films you increase the development time to 3’23”
  • When you develop the NEXT  16 films you increase the development time to 3’26”
  • When you develop the LAST batch of 16 films you increase the development time to 3’27”

At this point, Fuji recommends that you should not develop any more films with this batch of chemicals.

However, there are a few problems with this explanation:

  1. The mathematically sharp-eyed amongst you will have notice that 5*16 is 80, not 120. So either the maximum number of films that can be developed with a 5 litre batch is 80, rather than 120, or you should increase the batch size before increasing the development time, to 24 instead of 16. There are a few other threads on the web which suggest that this aspect of the Fuji instructions don’t make sense, so it’s hard to have confidence in the calculations.
  2. If you have the type of processor that allows you to program the development time exactly, then you can easily increase the development time by 3″ … but if you are filling and emptying the tank by hand then can you really be that accurate ?
  3. As I said above, most amateur users are going to want to mix smaller quantities because unmixed chemicals last longer than mixed chemicals. If you mix 5 litres in one go then there is a higher risk that the chemicals go “off” before you have developed the maximum theoretical amount of films than if you mix a smaller amount.
  4. Depending upon the make and model of your development tank, then the number of films you process at once might not be a divisor of 16, or 24. For example if you develop three films at a time then you would need to change the development time after 15 films instead of 16.
  5. In reality the degree of exhaustion of the chemicals will change gradually with each processing cycle rather than in a jump-step every 16 films, so the table can never be more than a guide.

So what do I do in the face of this confusion ? I operate a much simpler system.

I choose to mix 500ml of the chemicals at a time, and usually develop between 6 and 8 films using that 500ml batch, with a development time of 3’15”. This applies regardless of whether the films are 120, 35mm * 24, or 35mm * 36 exposures.  The C41 films I use are rated between ISO100 and 400 and I don’t distinguish between them. I don’t use any faster C41 films.

There is nothing very scientific about whether I mix new chemicals after six films or eight; if I have developed 6 films but it was some time since the batch was first mixed then I will probably mix a new batch, but if I have 8 films ready to develop in a short space of time, then I could do eight from one batch.

500ml of chemicals might not be the right amount for you because this depends upon the processing tank you use, and also whether you are using agitation or rotary processing.

Since I can mix ten 500ml batch out of the 5 litre kit, then in theory I will develop somewhere between 60 and 80 films from the kit. This is the capacity I have seen advertised for the kit.

I say “in theory” because I don’t think I’ve every reached the theoretical capacity with any C41 kit, whether it be Fuji Hunt, Tetenal, or Rollei Digibase, because I have a bid habit of doing something clumsy like knocking over and spilling one of the components.

On the other hand, there are those on the web who talk about reaching much higher capacities than those advertised. That might well be possible, but for my uses I want to stop before image degradation becomes apparent.

When I started writing this post, I had hoped to clear up some confusion, but I realise I may have added more. Such is life.

Kodak Ektar, shot in a Mamiya RZ67, and developed in the Fuji Hunt C41 kit.


  1. Hi Kevin, thanks so much for your explanations of the Fuji kit, much appreciated!

    We have one question, we are using the developer as one shot and are happy to be doing so, however we are mixing up 1 litre of Bleach and fix at a time and wondering roughly how many rolls we can develop with this before it’s exhausted. We are developing rotary on a Jobo. Any information greeted with thanks!


    • The short answer is lots, but it’s harder to be more exact than that. Since my kit makes up 5Litres of bleach and fix and is supposed to have a total capacity of around 100 films, then it’s reasonable to think you could get 20 rolls out of 1 litre of bleach or fix.

  2. Hi Kevin,
    Quick question, you say you prepare 500ml batches. How, where and how long do you keep these batches of solutions? I hear, freezing, fridge, protectan spray generally but would like to know your method as well.
    Many thanks,

  3. Hi Kevin, thanks so much for your really useful articles :). I’m moving from tetenal c41 to this kit, as it’s so much cheaper! Do you have any thoughts about chemistry expiry for moving image film? 100ft of expired Fuji 64d (I also have 250d that I want to process). I’m using a 2litre lomo tank, with 100ft at a time. Thanks in advance! 🙂

  4. Really appreciate the time you took to write this up! I just bought this 5L kit today and am excited to use it with our newly obtained jobo cpp2! I Plan to keep to the 4 week shelf life of the mix chemicals, but from your experience, how long would you estimate the unmixed concentrate will last if stored in say amber glass bottles?

    • Stewart, the longest time I have experienced between the first and last roll from a batch was six months. However the instrictions say, “for best results”, 6 weeks for the developer and 8 weeks for the bleach and fix. So going beyond that lifespan does clearly have a degree of risk.

  5. Hello Kevin, thanks for the article and thanks for the help really.

    I would like to know if you reused all chemicals on 500ml:

    for example if you have a 2 reel tank do the whole processing then put two more new rolls in the tank and use the same chemicals again until you reach 6-8 rolls or do you have to use in a tank that takes 6-8 rolls?

    Thanks Kevin

  6. Hi Kevin, I’ve just purchased a box of this C41 kit and found your blog which is very helpful. My question is: when you talk about making up all the solutions at once (i.e. 5l of each bath) and then re-using them to get to process 120 films (as per your table), would you be returning the used part (say 1 litre that you used to develop the first batch of film) back into the 5 litre bottle that now has 4l of unused chemical mixed with the 1l that you’ve just used? Or are you talking about the same 1 litre being used for 16 films first at the standard time, then another 16 films at a longer time etc.? My initial thinking was to mix 5l of each solution in a corresponding large canister with a tap, pour 1l into a smaller bottle for processing and then return the used chemicals back to the canister to mix with the fresh. But now I am thinking that this approach might probably need a different table than yours…?

    • Hi Martin, my routine would be to mix a small amount, say 1 litre, and use that 1 litre several times, then mix another litre. If you can be patient, it’s best to wait until you’ve already got a few films waiting for processing, before mixing each litre.

  7. Kevin, great info thanks. Shall be following your suggestions for 500ml split and 6 rolls per batch, it greatly simplifies things.

    I’d purchased this kit with the best intentions of shooting a metric pig-ton of film but I don’t think anyone saw the pandemic coming – what made sense at the time makes less sense now with a lot less to develop at once.

    How do you interpret the development agitation instructions for this kit? I find both the PDF and the printout supplied kind of lacking.

    It reads;

    1. Pour
    2. Tap base firmly
    3. 30 seconds constant agitation
    4. 13 seconds in water bath
    5. 2 seconds agitation

    At which point it reads;

    “Repeat this procedure for 10 seconds before the end of the processing step.”

    I wonder if this is a typo, as for the Bleach & Fixer steps it states;

    “Repeat these 30 seconds cycles until 10 seconds before the end of the processing step”

    As it is currently written, it suggests no further agitation until 10 seconds before the development step, where I wonder if what was intended is repeat the 15-second cycle (steps 4 & 5) until the 10 second pour at the end.

    Any clarification or your interpretation would be greatly appreciated!

Leave a Reply to Martin Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.