Phenidon-Ascorbate developer high base fog?

[grommi]

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

 

[georgegrosu]

I am not familiar with graphs of this type.
I use diagram density - log H. Probably is a error from write.
Fog density of 0.68 seems a bit high and not shown on the graph.

George

 

[Gerald C Koch]

I read Pat Gainers articles on phenidon/ascobate developers and tried to mix my own simple one shot developer.

Creating a useful and reliable developer is a very complex endeavor requiring among other thinks a good knowledge of photochemistry. It is not just dumping a bunch of chemicals into water. A point that I agued with PG over and over again. I doubt he ever really got the point of the argument. Check the current thread "Progress on XTOL-concentrate." to see just how difficult the problem is. The thread is now at 48 pages and still very active.

 

[albada]

I read Pat Gainers articles on phenidon/ascobate developers and tried to mix my own simple one shot developer. (...)

Reinhold,

Here's a simple one-shot developer I discovered last year. It uses only three chemicals, and gives quality near-XTOL:
(there was a url link here which no longer exists)

As Jerry and Michael R have pointed out, much testing is needed to qualify a developer. I am the person doing the work in the "Progress of XTOL-concentrate" thread. I've restricted myself to using only these chemicals: sodium sulfite, sodium metaborate, ascorbic acid, phenidone/dimezone. All except sulfite are dissolved in propylene glycol. That's a simple developer. But even after experimenting with it for a year, I'm still getting surprises. You should expect surprises. High fog was your first surprise. I assure you there are more. But I encourage you to experiment. I have made several new discoveries (at least, they are not in the literature). Perhaps you will make a discovery...

Mark Overton

 

[grommi]

Thanks a lot, Mark. To be honest, the "Progress on XTOL-concentrate"-thread makes me dizzy and I appreciate your simple PC-Sulfite formula.

I like simple formulas for a one-shot devloper that I can mix myself. P, C, and S are easily available, many other agents aren't like metaborate and borax or TEA, that are very resticted to buy for private persons where I live. BTW, I have the same P as you with CAS-# 92-43-3. I will try your PCS recipe, if I shouldn't be satisfied I still have my Caffenols I will report.

Thanks a lot everybody here at Apug. Best - Reinhold

 

[albada]

Thanks a lot, Mark. To be honest, the "Progress on XTOL-concentrate"-thread makes me dizzy and I appreciate your simple PC-Sulfite formula.

I like simple formulas for a one-shot devloper that I can mix myself. P, C, and S are easily available, many other agents aren't like metaborate and borax or TEA, that are very resticted to buy for private persons where I live. BTW, I have the same P as you with CAS-# 92-43-3. I will try your PCS recipe, if I shouldn't be satisfied I still have my Caffenols I will report.

Reinhold, I have learned more in the year since I discovered PC-Sulfite. If you decide to mix it, I suggest reducing the Phenidone to 0.10 g/litre. If you try it, could you post a response to that "PC-Sulfite" thread?

Good luck,

Mark

 

[grommi]

"If you try it, could you post a response to that "PC-Sulfite" thread?"

Yes, I'll do.

 

[Patrick Robert James]

I have been using a Phenidone/AA paper developer off and on for years and I have noticed that it needs a lot of restrainer to keep the whites clean on some papers. I stick with it though because it is easy to make.

I do seem to recall from my research a few years ago that it is better to use an organic restrainer with Phenidone so I use Benzotriazole not KBr for what that is worth to you. I am not an expert though so maybe someone who is can comment on that.

 

[Alan Johnson]

In this thread are curves for PC-TEA pH~9 and PC-Glycol (pH~10.5,my guess) ,there is nothing unusual about them, not much fog.

(there was a url link here which no longer exists)

One might expect the developer used by Reinhold, pH~9.5 to give a similar result.
One very simple question, the film was properly fixed?

 

[grommi]

One very simple question, the film was properly fixed?

Yep. I always do a clearing test.

 

[Zathras]

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

View 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