Wednesday, 20 June 2012

How To: Home Develop C41 Negatives

  Yes, its another post about developing.  Im in a very darkroom frame of mind at the minute as im currently in the middle of getting an enlarger setup in my spare room (going to look and probably buy tomorrow, yay).  Im thinking back to when i first started getting setup developing my own film and how i got lots of help from various forums but it still took me a long time to get all the information in required and to find a process that works for me.  So i thought that i would use my blog to pass on some knowledge to others, as well as my usual phototrip posts.

  So - this post is about my C41 process.  Unlike most others i started off doing C41 processing before i did black and white.  Most people start on black and white as its done (generally) at room temperature and there is more rom for error (yes, i know hardcore b&w enthusiasts will disagree, but lets just keep going).  However, many that get used to black and white seem to be under the impression that C41 is very complex and near impossible to do at home - but that just isnt the case.

  There are a few ways to do it.  Poeple get good results just getting a tub full of water and heating it up and if you fancy that route (lets face it, its cheaper) then go for it.  Personally i use a rotary processer - a Jobo CPE-2 to be precise.

  These are readily available on Ebay and all they are is a water bath with temperature control and a rotary motor which agitates your tank for you.  Some better (i.e. more expensive) models also have a lift which let you add and remove chemicals to the film tank without having to lift it off the rotary.  I find though that the CPE-2 easily meets my needs.

  As for chemicals i am a huge fan of the Rollei Digibase C41 kits.  I tend to buy from AG Photographic who are based in the UK as i have always had excellent servcie from them and they tend to be a little cheaper than everywhere else.  These kits come in a variety of sizes but i tend to go for the 1L kit which lets me do 4 batches of 250ml - around 20 films altogether.  These kits also have a long shelf life (when unmixed) which i find very handy as i often have a month or 2 where i dont have any films to process.  The only drawback is that the instructions that come with these kits arent the best.  There are washes missing and personally i think some of the times are off for processing which is why it took me so long to get my procedure nailed.

  So, what is my procedure?  Well, the Jobo tank i use allows for 1 x 120 film (or 2 x 35mm) to be processed (well, technically 2 x 120 films can go onto one reel but i dont like to do that).  I prefer to do my films one at a time simply for quality control - if something goes wrong during developing then i havent ruined multiple films.  I fill my Jobo with water (preferably warm as it means that you dont waste time and electricity heating cold water) and leave it to heat up to around 38C (C41 should be processed at 37.8 +/-5C).  I like to leave it to heat up for about an hour to make sure the temperature has stabilised.  Whilst the water bath is heating up i mix my chemicals following the instrucitons included with the kit.  The instructions say that they solutions must be mixed with water at 49C, and i am fortunate in that i can hit that temperature with the hot water from my taps.  If you cant then boil a kettle, pour the water into a jug and wait for it to cool down to around 49C.  The kit comes with multiple syringes - you need to make sure that you use one for fixer, one for stabiliser, one for bleach etc.  Use permanent marker to label them otherwise you will end up cross contaminating your chemicals.  Unfortunately there arent enough syringes included in the kit for 1 per chemical so i use the same syringe for parts A,B and C of the developer.  Some people may be renounce this but it works ok for me so i do it.

  So, you have measured out your chemicals and mixed them with water.  Pour them into their bottles, stir them well and put them into your water bath.  Whilst you wait for your chemicals to settle to 37.8C load your film onto your reels (if you dont know how to do this or even what im on about check youtube, theres lots of videos there that will help you out).  You're all set now and ready to develop (once your chemicals have heated up).  After about an hour dip a thermometer into your developer and check the temperature is stable at around 38C.  You will also need some jugs of water at around 38C too for washing yourn film later.  I like to fill a jug with a anrrow bottom and stand it in the spare space in my Jobo bath so the temperature keeps up.

  Once you're all heated up put your developing tank onto the rotary and set it going at full speed for 5 minutes.  This brings the tank and film up to a similar temperature to your chemicals which will stop your film being 'shocked' when you suddenly pour in some hot fluids.  Some people like to prewash their film.  They heat up the tank and then fill it with water for 3 minutes or so.  I used to do it but have personally gotten far better results by not doing so so i am dropping this step from my developing procedure.  If you google it you'll see a tremendous amount of debate covering this topic with everyone having a differing opinion about what effects prewashing/soaking has on the film.  If you do choose to prewash dont be worried when the water comes out a vivid colour like purple or green, this is the the anti-halation layer and dye being washed off your film.

  After 5 minutes it is time to start pouring in your chemicals.  Start your stopwatch and pour in your developer.  Put the lid on the tank and rotate the tank by hand 3 times so as to get coverage of the developer over the film, give the tank a solid tap on the floor/work surface to disoldge any air bubbles (remember this - it will make your film easier to scan later) then put the tank onto the rotary.

  My developing procedure is as follows:

Preheat 5:00
Developer 3:15
Bleach 6:30
Wash 1 3:00 (6 washes of 30s)
Fixer 6:30
Wash 2 6:00 (6 washes of 1m)
Stabiliser 1:30 (to be done at room temperature)

  With each step allow 7 seconds or so to pour out the first chemical and pour in the next eg pour the developer out at 3:08 and pour the bleach in at 3:15.  The washes are important steps but they are not included on the Rollei instructions.  The first wash should come after the bleach and consist of 6 changes of water every 30 seconds.  This makes sure that the tank is fully removed of bleach before you pour in your fixer.  The second wash comes after fixing and consists of 6 changes of water every 1 minute.  Again, this stops the stabiliser being contaminated by fixer.  Some people wash between developer and bleach but you really shouldnt do that as it can be detrimental to the process.

  Stabilising should be done at room temperature.  When you come to stabilise just pour it into your tank and rotate it by hand for the required amount of time.  I used to stabilise at 37.8C but i was advised by a fellow processor to do it at room temperature; to be honest though i cant see much of a difference in my negatives.

  The above steps should take you around half an hour to complete.  Once you're done you can take the lid off your tank and remove your film.  The film should be covered in foam from the stabiliser - dont wash this off.  Just hang your film up to dry naturally (in as dust-free an environment as possible).  Once its dry take it to your scanner or your enlarger and see how it looks.

  This tutorial is by no means definitive.  This is just how i currently develop my C41 negatives/cross processed slide films at home.  Im sure as time goes on i will home my skills in processing and change my process as i see fit.  If you have any quesitons feel free to post on this blog and ill be sure to answer them.