Monday, September 3, 2012

I recommend C-41 Dignan's processing method

After a period of tests on other alternatives to the classical C-41 processing method, I came to the conclusion that the Dignan's procedure is very reliable and I recommend it strongly.

But I would suggest following practical work method: make one liter of the bath A and store it in a plastic folding container. Use each time the necessary volume for the film you are using, some 300 ml for 35 mm films or 600 ml for 120 films. After use, put the the liquid back to the container and remove air. Each time you use it, it will diminished a little. Go on using until you have less than necessary to develop. At this point, make a fresh bath A and a fresh Bleach and Fixer or Blix if you prefer.

The bleach will be weaker and weaker with the time, the same with fixer or blix but the volume is kept and replaced by water, the same with fixer or blix.

I suggest following times:

Bath A - Fixed duration, always 10 minutes; it is said that the minimum is about 3 minutes but better more than less.

Bath B - Fixed duration, always 10 minutes, it will not overdevelop. This bath is used just once but I already reused it once some few days after and worked well.

Bleach of ferric EDTA - 10 minutes at room temperature, more than needed at 38ºC. Increase 30 seconds every time you use it.

Fixer of Ammonium Thiosulfate - 5 minutes, increase 30 seconds every time you use it.

If you are using Blix, 10 minutes, increasing 30 seconds each time.

With this procedure, your baths will last for at least 20 to 30 films until you reach 500 ml from the 1 liter bath A you made. It depends on the quantity carried to bath B. I always use a minimum of 20 to 25 ml per development. That is what remains in the tank after pouring it back to the plastic folding container.

The results are very acceptable, perhaps a little too pink sometimes but this is adjustable in scanner or software afterwoods.
Example I

Example II

Example III

Example IV
Note: The film I used is Agfa Plus 100 ISO and the camera is a Canon TLB 35 mm.

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