Living with Tetenal Eukobrom AC

Developer

Tetenal new Eukobrom AC is proving to be a delight to work with. I did not realize how much of a irritant the smell of the developer was until it had been removed from the equation. I no longer have developers nose where the smell lingers long after I have left the darkroom. 

In an early article on this developer I had a couple of questions: Personally the main questions yet to be resolved are its keeping qualities and whether or not the image will be warm when the developer starts to deplete. One of these has now been answered, that is it's keeping qualities. I have been using it in my slot processor, at the end of each print session I leave the developer in the slot and cover it with the lid. The amount of time between each print session varies a lot from days to weeks sometimes months.

Slot processor

 Two things have come to light. If you leave the developer in the slot you should give it a stir before you start using it again. The active ingredient can separate out dropping to the bottom. I was caught out thinking that the developer had come to the end of it's working life because it had been left for two weeks. Something I did regularly with Ilfords multigrade without loss of usability.

Something else I have not experienced before was a black and white crystalline substance on top of the stop bath. It was a very heavy build up making it difficult to remove the top off the stop. The stop it's self was clear and still at the level it had been left at, turning out to still be working even so I changed it. This maybe an interaction with the vitamin C - something to keep an eye on.

The other question about the warming of the prints as the developer depletes still remains unanswered. This due to the fact I have not processed enough prints with the fresh developer. Once I notice I'll let you know.

 

Finally I have used this developer with a number of makes of paper now - RC and FB, natural, warm, cool tone and tinted papers - With great results, so if you have not tried it yet, do so! you can get it in 250 ml shots which is More than enough to get a feel for the way it works and looks.

Technical Data:

Developer Tetenal Eukobrom AC, paper Kentmere RC gloss. 

Other Posts:
Eukobrom first look
FB papers in Eukobrom

Using RO9 special/ Studional as it was intended.

Negatives are FP4+ and Fomapan 100

I have had the opportunity to use RO9s/Studional as it was intended. Multiple development from the same batch of developer (1 litre will do 12 films). This is a new departure for me, I prefer the single use type. I was a little apprehensive with this decision but gathered four 120 format films together so I could put to the test the assertion that you can develop any number of film on the same day it was diluted without having to add a compensation factor for each film involved, as you do with other developers. This was something I had not heard of before.

Made using a Zero multi format pinhole camera.

 The two makes of film were FP4+ and Fomapan 100 in both cases at box speed. It just so happens that the dilution for these films is 1- 25 with a big time difference - four minutes for the FP4+ and ten for the foma 100.

As mentioned before in another article the developer has a syrup consistency to it as you pour it out. At this point I must add a warning because of the concentrated nature of RO9 special/Studional you need to take precautions when pouring it out to make up the working solution. I have found out to my cost that if you get it on your hands it has a nasty bite. Something I have not experienced when mixing up other developers.

Made using Bronica SQAi.

 With the developer made up the first film to be treated was the FP4+. I was curious to know how well the short process time would work. This will be the quickest I have ever produced the latent image. The actual time suggested was three and half minutes - you need to be careful of short times when it comes to processing film, so I upped it four minutes. Not a lot I know but it could mean the difference between a reasonable set of images and a good set. I can report that it was a good set of negatives with good density across the whole film. The next film out of the processing tank was the Fomapan 100 processed at the suggested time of ten minutes. Again a good set of negatives in fact when held up against the FP4+ film they looked Identical in density. To cut this short the third and fourth films were the same in look as their predecessors. I was not expecting such good results.

Made using a Bronica SQAi.

  The method I used was made up of my trusted inversion procedure and a returning of what was left of the 600 mls of developer back to the storage bottle. Let me explain, when you pour the developer out of the tank there is a a certain amount of fluid lost to this action. It is only a small amount but can be enough to stop the top edge of the film being fully immersed. With this in mind I poured the developer back into the litre bottle and then poured it out again into the measuring cylinder before each film processed. I could have just topped up the difference. This is me erring on the side of caution. This action may have rejuvenated any depletion that had occurred but I suspect that this is not the case with this developer.

Idle time between two batches	Development lengthened by
few hours (but development none *on same day)	None *
1 – 3 days	5.00%
4 – 8 days	10.00%
1 – 2 weeks	15.00%
over 2 weeks	20.00%

 
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RO9 special developer
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