I used a 0.5 % sodium Carbonate solution.Originally Posted by gainer
That's why I asked. I don't understand it either. If it's my Nikon F4 exposing for more than zone 0, I don't understand why this base density stays the same from zone 0 to zone III. And that on several different films. I will try another brand of ethylene glycol too. Maybe in this one there are additives influencing film development.You zeroed your densitometer on B+F, so the Zones that measured 0.4 surely can't be fog. They can oly be a mystery!
I'm not overly concerned about fog either. But I don't like the curve to start rising only at zone III or even more. An EI of two stops less is a PITA.Try using 1 tsp each of sodium carbonate and borax in a liter of water to dilute your glycol solution 1+50 for a quick and dirty test. This should give you a fairly linear plot from zones 2 on up with development of about 8 minutes at 70 F. If actual fog is too high for you, add some bromide to the working solution. I am not overly concerned about the fog I have seen, but if you use some of the alternative processes as Sandy does, double fog density means doubling an already very long exposure to UV light.
I guess I'm going to test the whole thing again with another camera, another brand of antifreeze, and bromide (one change at a time ofcourse). Restrictions on selling chemicals are very strickt here in Holland, so I cannot easily get chemical grade glycol or TEA. (I'm still looking for the Oil of Olaz variety of TEA )