Velvia 4×5 and Tetenal E6 one shot technique
February 20, 2013
I want a one shot process that gives me a maximum film yield of 12 films per 1000ml Tetenal working solution, and I want to process 12 4×5 sheets of film at a time.
After successfully trialling the Tetenal E6 3 bath kit on Velvia 4×5 50ISO, I intend to make some modifications to the procedures set down by Tetenal.
- First, I will be using a one shot technique, rather than the re-use technique, thereby eliminating the need for adjusted development times from chemical activity depletion.
- One shot has the potential to minimises the overall process time and it also avoids the risk of cross contamination of chemistry.
- One shot also avoids the problem of volume depletion of solutions, especially of the first developer, from the incomplete return of all solution.
- I intend to use the chemistry to obtain the full yield of films as recommended by Tetenal, ie 12 films per 1Litre of working solution. This is equivalent to 48 sheets of 4×5 (4 sheets of 4×5 = one 120 film =one 35mm 36exp film).
- For the developing I will be using a Jobo CPE2 processor with a 2550 drum and 2 4×5 reels, holding a maximun of 12 sheets of 4×5.
- The maximum volume of solution for my Jobo is 600ml. This will ensure all film is in contact with the solutions during agitation.
- I will be using only 250mls of working solution for each batch of 12 sheets. That’s because according to Tetenal, 1000mls of working solution has sufficient development activity for 48 sheets, therefore, by proportion, 250mls has enough activity for 12 sheets.
- Each working solution, once made up according to Tetenal’s instructions, will then be further diluted with water to make a total volume of 600mls.
- This act of dilution may require additional processing times which I will need to test. So far, my development times have been based upon visual inspection of my own film tests with a grey card.
When I get my next batch of chemistry I will test the times using my new proposed dilutions. If it all goes to plan I will post the results.