Sunday, September 16, 2012

Just another Caffenol

In this post I will try to describe how I came to the idea of ​​a Caffenol that can in principle be stored in concentrated solution for use when needed.

The idea of ​​using sodium sulfite in caffenol baths came from Reinhold, author of the excellent blog Caffenol, to reduce the grain of caffenol, making use of the solvent properties of sulfite. But sulfite is also a preservative and, in some developers, it is used as alkali to activate the developer agents. This means that it can be used for other purposes.

Then, Mike, a fellow in Flickr, that also has a fine blog (already added to my list) , had also the idea of a Caffenol 2-bath developer. I entered the discussion and started working in the same direction. But due to a bad choice, I was led to another result that may also be useful: a concentrated caffenol. Mike, the author of the topic about 2-bath caffenol, succeeded with a recipe using more Vit. C than coffee, with very good results.

My recipe consisted first in a 5% bath of sodium carbonate, washing soda, with just 5 ml/L of the concentrate developer agents. The concentrate is made of 200g/L coffee, 200g/L Vit. C and 100g/L sodium sulfite. 5 ml contains only 1g/L of coffee and 1g/L Vit C and 0,5g/L sodium sulfite. Below is a photo developed with 5ml/L of the concentrate in a 5% solution of just soda. The film is strong fogged, but the pictures are very acceptable. It took only 15 minutes to develop, like regular caffenol baths.

A Slice of house

Then I saw that Potassium Bromide should be added to bath B, in order to get less fog. I did it and exposed a second roll but I had to make some adjustments now. Using just 1g/L of Bromide is enough to slow very much the development. So I replaced 5ml of bath A with 10ml and I have prolonged the 15 minutes time to 30 minutes. So, the new recipe means: 2g/L coffee 2g/L Vit. C 1g/L Sodium Sulfite 1g/L Potassium Bromide 50g/L Sodium Carbonate.  This time I took some pictures without leaving home, from the windows to outside, with the new Holga GN. After development, no fog at all, but poor focus of the camera and grain as usual in Caffenol but not bad.

View from the front window

This test showed me clearly that I could shoot another roll with the better camera Adox Golf, the same I used with the first roll. I don't have a better camera, but I think I need a medium format camera with a better lens for these 'good developers'. This reminds me of my cheap bicycle where I installed a powerfull electric motor and the bycicle is now broken because it is to weak for the motor.

And here are two examples of the last of three rolls developed with the concentrated caffenol solution, just another caffenol but maybe cheaper than the others or somehow practical.

Across the river

About the stadium in Leiria

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