Phenidon-Ascorbate developer high base fog?
I read Pat Gainers articles on phenidon/ascobate developers and tried to mix my own simple one shot developer. That's what I mixed:
4 g/l sodium carbonate anhydrous
4 g/l ascorbic acid (pure)
0.5 g/l pot. bromide
0.1 g/l phenidone
Added in given order. I use stock solutions of phenidone in glycol and bromide in a. dest.
pH is about 9.5
I used Pats recommended relation of ascorbic acid / phenidone = 40/1. Negs are of low contrast and underdeveloped, but base fog is very high: 0.68 with HP5+. See graph below, red curve, exposed as Iso 800, real speed about Iso 200 with low gamma, all densities above base fog = 0.68.
Developed 10 minutes 20 °C, agitation first minute cont., then 3x every 60 sec. If I would increase development time I will get even more base fog. What's wrong here? Is this developer prone to exessive base fog? Any suggestions?
Best - Reinhold