Phenidone vs. dimezone?

bluechromis · Nov 21, 2020

I've read that the dimezone S variant of phenidone has better keeping properties than regular phenidone but otherwise works in the same way. I have had bulk phenidone go bad. All things being equal, is there any reason why it would not always be better to use dimezone S instead of phenidone? I get that established developer recipes based on phenidone might need to be reformulated to use dimezone S and that would be a complication. From what i can tell with PF dimezone S is a little cheaper than phenidone but both are used in such small quantities price may not be a major concern.

BradS · Nov 21, 2020

I don't know the answers to your questions but I'm curious. How did your Phenidone go bad or rather , how do you know it is bad? did it turn brown or something? I have kept a bottle of approx. 100g of phenidone in the fridge for something like 15 years. Mine seems fine. I used a little bit from the initial 100g, decided I didn't care for phenidone and went back to metol...but I've never suspected that it would go bad.

Anon Ymous · Nov 21, 2020

I'd like to know how it went bad as well. I bought mine back in early 2014, so have it for almost 7 years. It came in a plastic bottle and was light yellow/tan. It's still exactly as I bought it and seems perfectly fine. Always kept it at room temperature.

bluechromis · Nov 21, 2020

BradS said:
I don't know the answers to your questions but I'm curious. How did your Phenidone go bad or rather , how did you know it was bad? did it turn brown or something? I have kept a bottle of approx. 100g of phenidone in the fridge for something like 15 years. Mine seems fine. I used a little bit from the initial 100g, decided I didn't care for phenidone and went back to metol...but I've never suspected that it would go bad.

The way I discovered the problem with my phenidone was that the activity of new batches my developers, Instant Mytol or PC-TEA, PG110B, would mysteriously decline over time compared to batches with recently purchased phenidone. I don't mean the stock failed in storage but that new batches were progressively weaker from the get-go. So I tried replacing the ingredients with newly purchased bulk supplies one at a time and found the phenidone was the culprit. In "The Film Developing Cookbook" Anchell and Troop say that phenidone does not keep well in stock solutions but I don't know if that has any bearing on dry power. I believe I got the phenidone from PF.

Anon Ymous · Nov 21, 2020

@bluechromis What colour was your phenidone?

john_s · Nov 21, 2020

Using Dimezone-S in a formula instead of phenidone, it seems "reasonable" to adjust for the greater molecular weight of Dimezone-S (x1.27).
I have read several comments over the years that suggest a greater adjustment is necessary. Also that the extra adjustment depends on whether or not the developer is highly dilute (e.d.Pyrocat-HD) or fairly concentrated (e.g. Microphen-like). I really don't know. I tend to copy such snippets and could find them if anyone is interested.

I am heartened by Sandy King's comments here at APUG about the amount of phenidone in Pyrocat-HD that within a range it makes no difference (but this was not directly about Dimezone-S).

bluechromis · Nov 21, 2020

Anon Ymous said:
@bluechromis What colour was your phenidone?

It is just a bit off-white buff color.

Anon Ymous said:
@bluechromis What colour was your phenidone?

It seems like a slightly off-white buff color

bluechromis · Nov 21, 2020

Anon Ymous said:
I'd like to know how it went bad as well. I bought mine back in early 2014, so have it for almost 7 years. It came in a plastic bottle and was light yellow/tan. It's still exactly as I bought it and seems perfectly fine. Always kept it at room temperature.

I am glad to hear it is keeping well for others. Maybe my problem with it was a one-off thing.

Anon Ymous · Nov 21, 2020

bluechromis said:
I am glad to hear it is keeping well for others. Maybe my problem with it was a one-off thing.

@Ian Grant probably has some phenidone from the 70s, still working fine.

Patrick Robert James · Nov 21, 2020

I mix Phenidone and Dimezone-s in Propylene Glycol when it is fresh. Easy to measure that way as a percentage too. And it last forever.

Ian Grant · Nov 22, 2020

Anon Ymous said:
@Ian Grant probably has some phenidone from the 70s, still working fine.

A decade out 1960's

I've said many times before I have Ilford Phenidone made in 1961 that still works as well as fresh Phenidone. British books all state Phenidone keeps ell, US books said it keeps poorly but I think this was misinformation when Kodak were trying to sell Dimezone-S.

What I have noticed is commercial PQ developers made with Dimezone-S don't keep quite as long as the older Phenidone versions particularly once opened. Looking at the OP's photo that Phenidone looks fine.

Ian

Rudeofus · Nov 22, 2020

The main difference between Phenidone and Dimezone-S is not bulk storage, but storage in alkaline solution. Phenidone hydrolyzes in alkaline solution, Dimezone-S does not. Since most paying customers hate two/three solution concentrates, and have nothing but contempt for powder bags, Dimezone-S is the clear winner here.

@Ian Grant : if Phenidone had any merit in liquid concentrates, Ilford would definitely use the much cheaper Phenidone. They don't, and probably for a reason.

Ian Grant · Nov 22, 2020

Rudeofus said:
: if Phenidone had any merit in liquid concentrates, Ilford would definitely use the much cheaper Phenidone. They don't, and probably for a reason.

The change came when Ilford out-source their chemistry manufacture to Chamion, all the formulae used to use Phenidone before that, it appears Champion could get Dimezon-S cheaper perhaps they manufactured it. Much of their chemistry is based on May & Baker products who through various takeovers the non pharmaceutical side came under the Champion name. May & Baker made all sorts of raw photo-chemicals at one time, the current Champion range of Colour & B&W chemistry still use the May & Baker trade names.

Around the time of the change I was told by someone at Ilford the change was down to cost. Phenidone is still used in two Ilford powder developer Bromophen & Microphen both of which use a small amount of Sodium Metabisulphite as a preservative in Part A.

Ian

Rudeofus · Nov 23, 2020

Ian Grant said:
Around the time of the change I was told by someone at Ilford the change was down to cost. Phenidone is still used in two Ilford powder developer Bromophen & Microphen both of which use a small amount of Sodium Metabisulphite as a preservative in Part A.

Ilford was supposed to change all their liquid developers to Dimezone-S for cost reasons, but for whatever reason their powder developers stuck with good old Phenidone. Sorry, but this does not look like a cost cutting effort, but a hydrolysis prevention effort, regardless of what Ilford may have told you.

Ian Grant · Nov 23, 2020

Rudeofus said:
Ilford was supposed to change all their liquid developers to Dimezone-S for cost reasons, but for whatever reason their powder developers stuck with good old Phenidone. Sorry, but this does not look like a cost cutting effort, but a hydrolysis prevention effort, regardless of what Ilford may have told you.

Well I'd been using Ilford PQ Universal since the early 1970's and later Multigrade developer as well. When the switch was made the shelf life dropped. In more recent years I've mixed my own concentrated PQ developers using Phenidone (presumably Phenidone-A) and it keeps just as well as the older pre Dimezone-S Ilford commercial developers. For just over five years while I was living abroad my developers here in the UK were only used a couple of months each year and even then only for 2 or 3 intense printing sessions every return trip. I found the developer lasted well up to 2 years, Pyrocat HD up to 4 years made up in water.

Ian

Rudeofus · Nov 23, 2020

It has been a common pattern here on photrio, that your experiences with photo chemistry do not line up with those of most others. Adox MQ Borax is the best developer of all times and beats XTol like a drum in every aspect, Phenidone has near infinite shelf life both in powder form and in alkaline solution, whereas Dimezone-S in any form rots away instantly just like uncooked fish. This is just what I remember on top of my head, I am sure there is more.

These may indeed be your personal experiences, but they may not be an indicator of other people's experiences.

PS: There is a chance, that Ilford had much more Phenidone in their original PQ Universal to compensate for its hydrolization, and that the cost savings came from replacing it with much less Dimezone-S.

Ian Grant · Nov 23, 2020

Rudeofus said:
It has been a common pattern here on photrio, that your experiences with photo chemistry do not line up with those of most others. Adox MQ Borax is the best developer of all times and beats XTol like a drum in every aspect, Phenidone has near infinite shelf life both in powder form and in alkaline solution, whereas Dimezone-S in any form rots away instantly just like uncooked fish. This is just what I remember on top of my head, I am sure there is more.

These may indeed be your personal experiences, but they may not be an indicator of other people's experiences.

PS: There is a chance, that Ilford had much more Phenidone in their original PQ Universal to compensate for its hydrolization, and that the cost savings came from replacing it with much less Dimezone-S.

Who has said that Adox Borax MQ is the best developer of all time ? or that it beats Xtol ? I definitely haven't, yes I found Adox Borax MQ slightly better than ID-11/D76 back in the 1980's but I've always thought Xtol is better still which was why I switched to it when it was released.

The longevity of commercial Phenidone is well known, Dr Curt Jacobson made this clear many decades ago and so did LFA Mason (of Ilford). I have never I said that Phenidone based concentrated PQ developers have indefinite shelf lives rather an observation also noted here by others (in threads here) that the newer Dimezone-S versions don't seem last quite as long before oxidising but these are slight rather than huge differences.

Mason does discuss the poor keeping properties of the original Phenidone but then states that was why Ilford used Phenidone A & B and Kodak Dimezone-S, Mason as Head of Ilford Research knew what he was talking about and his editor was a counter part at Kodak.

In a series of articles in the British Journal of Photography in the late 1950's early 1960's Ilford Research discus the formulation of a new PQ version of ID-11 which they sold as Autophen, it's in Jacobson Developing as the Axford Kendall Phenidone-Hydroquinone Fine Grain Developer with two different replenishers. There's a comment on how one lab has just replenished their film processor for a number of years never dumping a starting a fresh batch.

Ian

Ian Grant · Nov 23, 2020

PQ Developer of long, even infinite, life.

The developer worked out to produce negatives of the type required by photofinishers and to have a long, even indefinite, life is marketed by Ilford Limited under the name- “Autophen”. Extensive trials in the laboratory and under practical photofinishing conditions show that it fulfils the requirements very well. Variations in characteristics of the developed image in one of the field trials are shown graphically. A 24-gallon tank was used and a total of 65,000 rolls was put through with topping-up replenishment using the replenisher designed for this purpose. Periodic spectrometric tests indicated that over the relevant period corresponding to over 2000 rolls per gallon of fresh developer the relative speed (at a density of 0.l above fog) varied by about ½ stop, tending to level out at approximately the same value as that of the fresh developer. Contrast, measured by an average gradient over a 1.5 log E range, tended to stabilise a little below its initial value, the range being from 0.67 to 0.78 with an initial value of 0.75. Fog was likewise closely controlled. The tests therefore showed that an equilibrium developer condition could be established which was very close to the condition of the original solution, and the question of the ultimate life of the developer then hinged on considerations other ` than the maintenance of photographic quality. The practical limit is usually set by the accumulation of sludge and dirt in the developing tank. During a season’s work this should not be troublesome, but over two or more years may affect the negatives produced.

B.J., 1957, June 14, p. 342.

Ilford's research dispels the myth of Phenidone not keeping well in solution.

Ian

john_s · Nov 23, 2020

Ian Grant said:
....... the relative speed (at a density of 0.l above fog) varied by about § stop,........

Ian

Just as a matter of interest, on my Windows computer, a number before the word "stop" shows as an irrelevant symbol. I assume that it's an extended symbol for a fraction, and I'm curious to know what it is, maybe a half or a quarter?

Ian Grant · Nov 23, 2020

Rudeofus said:
PS: There is a chance, that Ilford had much more Phenidone in their original PQ Universal to compensate for its hydrolization, and that the cost savings came from replacing it with much less Dimezone-S.

Sounds like your on magic mushrooms. Ilford's formulae work exactly as they should with the right amount of Phenidone certainly no extra, as do many other companies PQ concentrated developers using Phenidone. Orwo/Calbe, Fotospeed, Foma, Agfa, Kodak, and many more.

Ian

Ian Grant · Nov 23, 2020

john_s said:
Just as a matter of interest, on my Windows computer, a number before the word "stop" shows as an irrelevant symbol. I assume that it's an extended symbol for a fraction, and I'm curious to know what it is, maybe a half or a quarter?

I'll check tomorrow, sometimes OCR software miss interprets fractions and I and spell checks miss the Symbol . I think it's going to be around 1/3 a stop.

In many US books the Autophen formula was mistakenly assumed to be that of Microphen. Reality was though Ilford realised the slight speed increase in the Autophen PQ variant of ID-11/D76 and tweaked it further to make ID-68/Microphen essentially dropping the Sulphite level to a more optimal level. The sulphite level of 75 to 80 gms per litre gives better sharpness/definition as well as tonality and box fil speed via better shadow detail.

To Rudeofus, I'm not suggesting using Autophen, rather it was once a huge selling developer in the Photo Finishing industry. I have a n early 1960's Ilford price list and it was sold in large scale packaging as a liquid and powder, not suitable for amateurs.

Ilford also published how they analysed PQ developers and that included how efficiently the Phenidone was working, at the time that was light years ahead of Kodak research.

Reality Rudolp is quite different.

Ian

Ian Grant · Nov 24, 2020

john_s said:
Just as a matter of interest, on my Windows computer, a number before the word "stop" shows as an irrelevant symbol. I assume that it's an extended symbol for a fraction, and I'm curious to know what it is, maybe a half or a quarter?

It should have been 1/2 a stop.

Ian

albada · Nov 25, 2020

@Rudeofus - In what ways is Adox MQ Borax better than Xtol? Are these your experiences with it?
Also, what is your formula for it? My notes and web-sites say: Metol 2g, Sulfite 80g, Hydroquinone 4g, Borax 4g, P.Bromide 0.5g. But page 44 of The Film Developing Cookbook says Metol is 1g. That difference of 2g vs 1g will have a big effect.
Mark Overton

Ian Grant · Nov 26, 2020

albada said:
@Rudeofus - In what ways is Adox MQ Borax better than Xtol? Are these your experiences with it?
Also, what is your formula for it? My notes and web-sites say: Metol 2g, Sulfite 80g, Hydroquinone 4g, Borax 4g, P.Bromide 0.5g. But page 44 of The Film Developing Cookbook says Metol is 1g. That difference of 2g vs 1g will have a big effect.
Mark Overton

Mark, the FDC is wrong, you have the right formula.

What @Rudeofus was saying was that I thought Adox Borax MQ was the best developer, and better than Xtol, In fact you will find I've always thought that it was slightly better than D76/ID-11 as the Sulphite level is better optimised, giving sharper finer grain results more detail in the highlights, slightly cleaner working, overall slightly better resolution, But you could say the same about Agfa 44/Agfa Ansco 17 which is similar and like Adox-Borax MQ/EFKE FR2 both were once sold commercially.

However Xtol is the next step further so after testing it on it's release I switched to it mostly for commercial work. By then I'd moved from FP4 to Agfa AP100 and then APX100 released maybe a year later, and Tmax 100 as a backup. It was some years before I discovered the professional dealer always had Agfa films, Rodinal, and Record Rapid paper on the shelf but I was the only customer buying it. Sometime there wasn't enough film so hence Tmax 100 but the downside was for the same tonality & contrast I needed to shoot Tmax 100 at 50EI while AP/APX100 was fine at 100ISO.

But this deviates from the merits of Phenidone.

Ian

Rudeofus · Nov 26, 2020

albada said:
Also, what is your formula for it? My notes and web-sites say: Metol 2g, Sulfite 80g, Hydroquinone 4g, Borax 4g, P.Bromide 0.5g. But page 44 of The Film Developing Cookbook says Metol is 1g. That difference of 2g vs 1g will have a big effect.

Evidently there were two versions of this formula floating around, and earlier editions of The Film Developing Cookbook (I only have 3rd and 4th edition here) contained only the version with 1 g/l Metol. The latest edition of The Film Developing Cookbook states:

... and in the Adox Standard MQ Borax formula, which is as follows: metol 1 gram [2 grams according to Haist], sodium sulfite anhydrous 80 grams, hydroquinone 4 grams, borax 4 grams, potassium bromide 0.5 grams, water to 1 liter.

Phenidone vs. dimezone?

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