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  1. #11
    grommi's Avatar
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    Quote Originally Posted by Alan Johnson View Post
    One very simple question, the film was properly fixed?
    Yep. I always do a clearing test.

  2. #12
    Zathras's Avatar
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    Quote Originally Posted by grommi View Post
    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

    Attachment 64129
    Hi Reinhold,

    Have you read this article by Patrick Gainer at unblinkingeye.com? Neat the end of the article he shows different variations of the developer in two tables.

    Your formula is not the same as the formula Gainer describes in the article. I think that the main cause of the problem is too much phenidone in the developer. How much dry phenidone are you actually dissolving into a liter of developer? If you are indeed using .1 grams of per liter of developer, then you have 5 times the required amount in your developer. The correct amount is closer to .02 grams per liter. Gainer added 2.5 ml of a phenidone solution to a liter of developer. He made this solution by dissolving .65 gram of phenidone in 80 ml of 90% isopropyl alcohol or denatured alcohol.

    You also have 2 times the required amount of ascorbic acid in the developer. The amount of sodium carbonate anhydrous should be 5 gams per liter. I think that the excess phenidone and ascorbic acid are causing all the trouble.

    I think you would have better results if you mixed the formula as follows;
    Water 20C 750ml
    4 g/l sodium carbonate anhydrous Keep this the same for now, since the quantities of ascorbic acid and phenidone will be reduced.
    2 g/l ascorbic acid (pure)
    2.5 ml phenidone solution
    Water to make 1000ml

    You may find that the potassium bromide is not needed.

    I hope this helps, Post back if you try this, and let us know what the results are.

    Mike
    Last edited by Zathras; 02-16-2013 at 01:06 AM. Click to view previous post history.
    When the chips are down,

    The buffalo is empty!!!



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