Monday, April 28, 2014

My submission to Worldwide Pinhole Photography Day

Yesterday I took my old Agfa Synchro Box adapted as Pinhole, with a focal lenth of 100 mm and a hole of 0,5 mm f number 200, and exposed a Shangai GP3 120 roll giving about 3 seconds exposition. Some of them were underexposed because I didn't count on shadows and trees. But I've got the best sharpness of all attempts I made before in Pinhole Photography.

And I choosed this photo, entitled «Ghosts on the Bridge» to submit to the contest of the WPPG organization here:

Photo taken on the 27th April in Leiria, Portugal
Notice: I couldn't upload this photo, checked some days after if it was in the gallery, but didn't find it. There was no feedback at all when I uploaded so I tried again with another photo from the same day and the same camera but using expired Fujicolor 100:

Saturday, April 26, 2014

Pinhole Day is tomorrow

Yesterday I went until the site of Pombal, near Leiria where I live. Knowing that next 27th April, tomorrow, is the Worldwide Pinhole Photography Day, I took my Agfa Synchro Box modified as Pinhole Box. In Pombal, I visited the Castle and took there or from there some pictures with my box. Later, at home, I developed the roll, an Agfapan 400 expired since 2001 using my Black Coffee developer. Here are two samples of the 8 pictures that the Box can take with a 120 roll film. This film came a little brownish, slightly fogged.

Sunday, April 20, 2014

Black Coffee

In a recent discussion at Flickr involving someone who wanted to give up of caffenol, because it produces fogged negatives and stained, I came to the conclusion that, on the contrary, coffee is an excellent developer and doesn't need lots of stuff to give good results. My minimal recipe, that I call Black Coffee is as follows, for 1 liter developer:

20 g soluble coffee dissolved in about 750 ml water. Add 0,5 g (more or less) of Sodium Hydroxide. Complete with water to make 1000ml.
It is important that you reach a pH of 11,4 to 11,6 and the amount of Sodium Hydroxide will depend on coffee quality and also of the water used.

Develop for at least 60 minutes in stand or semi-stand development at room temperature.

To measure 0,5 g of sodium hydroxide, make a solution of 10% (100g/liter) and measure some mililiters of that. Go on slowly and stiring to reach not more than 11,6 pH.

Give it a try and tell me later about!

Friday, April 18, 2014

C41 at room temperature

In the last post I showed you the influence of pH in the color saturation and shift. I am now more or less convinced that a higher pH produces the same effect of the temperature for a sodium carbonate based developer.

The last film I developed came out with much more acceptable colors and I used Dignan's 2-bath methode, but the second bath was a 5% sodium carbonate solution with sodium Hydroxide q.b to rise the pH to 13. I also added 0,6g/L of Potassium Bromide in order to avoid some fog.

The only problem now to be solved is the high grain amount of the negatives. The film exposed before this last one came unusable, underdeveloped because the amount of Potassium Bromide (2g/L) was to high and even 15 minutes of the 2.nd bath development produced a almost blank film. So I decreased the amount of Potassium Bromide to 0,6g/L and prolongue the development to 20 minutes (it is said that with Dignan's methode overdevelopment is impossible). I agitated the whole time but maybe too much. This could be the reason of these grainy photos made with a Fujicolor film of 400 ISO that also contributed to the grain increase.

Saturday, April 5, 2014

What is behind temperature in C41 process?

For many years my hobby has been B&W photography and I used brand chemicals to develop my films and prints. I never supposed it possible to develop color at home, even professional photographers were sending the films to more sofisticated laboratories to process clients requests.

For more or less one year, or more, I started developing C41 films. OK, first I baught a kit from Tetenal and studied what each thing does. The great handicap for many of us, by processing C41 is that the developer should be mantained at 38,5ºC, continuos agitation and last 3' 15''. This is only possible with a automatic film processor.

But many purists follow exactly those steps in order to achieve the best of their photos. I am not a purist and very distracted, I could give 16'' instead of 15'', eheheheh!

By chance I discovered Dignan's 2-bath developer, which is safe against idiots and distracted people, don't need temperature and don't need exact timing. I have read that article several times and one detail called my attention shortly: original Dignan's 2-bath developer used as second bath Potassium Carbonate whose pH is greater than that of Sodium Carbonate.

But in the Tetenal kit one of the bottles contained just Sodium Carbonate.

Dignan's 2-bath is OK, gives some color shift but in some cases makes the picture look very artistic. But as photographs that intend to reproduce exactly the objects, it is not advisable.

So, when I developed one of my last color films, I decided to use Sodium Carbonate but at more or less the recommended temperature, about 40ºC. But I measured the temperature and the pH of the bath. Aha! The solution of Sodium Carbonate had a pH of 12,6 when at 20 ºC the pH is said to be 11,6.

Then I came to the supposition that the temperature was needed to rise the pH of the bath. To be sure of that, I prepared a 1% solution of sodium Hydroxide with pH at 13,4 cold and used it as the second bath. The result is that the pictures came with much more color saturation.

Full color

I had to dessaturate them to achieve a more acceptable color picture:

Full color

Next time I will prepare a buffer solution with pH = 12,8 to be used at room temperature and hope to get the right degree of color saturation.