Wednesday, February 22, 2012

Lowering the temperature without loosing color

Yesterday night I was so tired that when developing the last stripe of negative color film, I forgot using the recommended high temperature, and only too late I noticed that. So, the whole process took place at 16 ºC, that is my room temperature at this time. I was quite sure I would get nothing to see but, hold the air, yes, there was something on the film. Very thin, would give bad positives, but there was some color image on  it. I used the developer like I did before - see last post.

Then, having in attention that the previous experiment gave a very dense negative, I decided to lower a little the temperature and I fixed it in 27ºC, but only for bath B, the other baths were used at room temperature.  The results are very encouraging, but something must be adjusted, the bleach bath, I think, is damaging the images. I already told that this bleach is very strong, it washes the color out if the time is exceeded. This action took place in the last two pictures out of nine, that are blurry. In these pictures the border zones where probably attacked by the bleacher. I have to dilute it more or change to another substance more suitable for color films. This is a B&W reversal bleacher that I am using because I had the substances at home, Potassium Dichromate and Sulfuric Acid and I don't want to use the Tetenal ones.

One of the first pictures

For last picture
The last picture
Resume table for the procedure:

Bath
Duration /min.
Temperature / ºC
Obs.
CD-4
5
R.T.
Continuous agitation
Caffenol*
10
27 Continuous agitation
Stop
1
R.T.
Continuous agitation
Bleach
2
R.T.
Continuous agitation
Rinse
1
R.T.
3 times fill
Fixer
5
R.T. First minute agitation
Washing
30
R.T.
3 times fill and then take from tank and leave in water
Dry
90 min.
R.T.

R.T. was at 16ºC

Maybe it is possible to lower the temperature to 20ºC if the developing time is extended to, let us say, 20 minutes?

* The Caffenol I used here was made of 9g Sodium Hydroxide, 20g  Sodium Bicarbonate and 14g coffee. It is a stronger developer than the other with washing soda. The same substances for bath B without coffee doesn't work well, I tried before.

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