Perceptol & The Microdol Substitute Formula.

[Keith Tapscott.]

Has anyone tried comparing `Edgar Hyman`s Microdol substitute formula with Ilford Perceptol? If so, did you notice any difference between the packaged product and the home made developer?

Edgar Hyman’s Microdol Substitute Formula:

Metol....................................5 grams
Sodium Sulphite, anhydrous........100 grams
Sodium Chloride (iodine-free)... 30 grams
Water to make.......................1 litre of stock solution.

 

[George Hart]

What is the purpose of your question?

 

[Keith Tapscott.]

What is the purpose of your question?

The purpose of my question is that if the published formula mirrors the Ilford product, then I can make it my self and save money. Also I can make as much as I need without being restricted to making 1 litre of it at a time.

 

[Nicholas Lindan]

The formula works - it develops film - but I wouldn't use it with modern films as it deposits dichroic fog. Kodak, and I am sure Ilford, add a silver sequestering agent, probably a mercaptan like aminopolycarboxylic acid. Perceptol is also thought to contain P. Bromide in a bid to gain a bit of speed by reducing fog levels.

 

[Keith Tapscott.]

The formula works - it develops film - but I wouldn't use it with modern films as it deposits dichroic fog. Kodak, and I am sure Ilford, add a silver sequestering agent, probably a mercaptan like aminopolycarboxylic acid. Perceptol is also thought to contain P. Bromide in a bid to gain a bit of speed by reducing fog levels.

Thanks, I wont bother with this formula.

 

[Ian Grant]

Surprisingly the formula works perfectly with some modern films (I only tested 2) and no fog is produced, it was 50's and 60's films that had big dichroic fogging issues, and this was less anyway with Chloride than with the Thiocyanate in DK20.

A part from a mistake on an Ilford MSDS listing Bromide in Pt B at an alarming level, instead of Chloride, it's unlikely any bromide is present.

Ian

 

[Tom Kershaw]

Ian,

Do you know whether ILFORD updates their MSDS and technical sheets to correct error? It is frustrating that ILFORD / Harman product information PDFs don't give as much information as Kodak's.

Tom

 

[Ian Grant]

They did, then later rationalised them, Ilford MSDS's now give very scant information the minimum amount of detail necessary.

Ian

 

[Tom Kershaw]

Rationalised the information sheets?

Tom

 

[Ian Grant]

No rationalised the MSDS's, so that they were simpler and only show the chemicals over 1% that are Hazardous, so Perceptol PartA shows the Metol, and Part B just the Sulphite, as the Sodium Chloride isn't deemed hazardous.

Ian

 

[Tom Kershaw]

Perceptol may be related to the above formula then?

Tom

 

[Ian Grant]

We know it's very close, this is from the pre 2002 MSDS:

Iford MSDS for Perceptol:

PERCEPTOL DEVELOPER, Part A contains
Methyl p-amino-phenol Sulfite (Metol)

PERCEPTOL DEVELOPER, Part B contains:

Sodium Sulphite
Sodium Chloride
Sodium Tripolyphosphate

So it is like D-23 plus Sodium Chloride and Sodium Tripolyphosphate, the later is a sequestering agent and can be left out.

It's generally accepted that the amount of Sodium Chloride is 30g.

Ian

 

[Keith Tapscott.]

We know it's very close, this is from the pre 2002 MSDS:

Iford MSDS for Perceptol:

PERCEPTOL DEVELOPER, Part A contains
Methyl p-amino-phenol Sulfite (Metol)

PERCEPTOL DEVELOPER, Part B contains:

Sodium Sulphite
Sodium Chloride
Sodium Tripolyphosphate

So it is like D-23 plus Sodium Chloride and Sodium Tripolyphosphate, the later is a sequestering agent and can be left out.

It's generally accepted that the amount of Sodium Chloride is 30g.

Ian

Ian, have you ever compared this formula with Ilford Perceptol as packaged?

 

[Nicholas Lindan]

Sodium Tripolyphosphate, the later is a sequestering agent and can be left out

It is likely the S. Tripolyphosphate sequestering agent's purpose is to prevent dichroic fog by sequestering the silver dissolved by the S. Sulfite.

Best left in...

 

[Keith Tapscott.]

It is likely the S. Tripolyphosphate sequestering agent's purpose is to prevent dichroic fog by sequestering the silver dissolved by the S. Sulfite.

Best left in...

I found this post about Perceptol on another photo-forum....

Would you be interested in the formula for 'Perceptol'? I got it from a bloke who worked in Ilford's Woodman Road, Brentwood factory when it was being closed and all the gear was being given away to photo colleges or thrown away and workers lost their jobs.
Sodium Tripolyphosphate 3.5 gms
Metol 5.0 gms
Sodium Sulphite anhyd.100.0 gms
Sodium Chloride 30.0 gms
water to 1 Litre
I suppose the Sodium Tripolyphosphate could be left out if SOFT or DISTILLED water is used.

 

[Photo Engineer]

There are several patents on inhibitors of dichroic fog, one of which is supposedly used in Microdol X. Kodak does indeed use a dichroic fog inhibitor in the M-X formula, it was patented, and is not on the MSDS. That is all I know that is of any help right now. The Sodium Tripolyphosphate is equivalent to Calgon or some other sequestrants to inhibit formation of sludges in developers when mixed with hard water.

PE

 

[Keith Tapscott.]

Another Metol + Sulphite formula I found in a BJP annual is Ferrania R-33 which is simply a weaker version of the Kodak D-23 formula.

Ferrania R-33:

Metol = 5 grams
Sodium sulphite, anhydrous = 100 grams
WTM 1 litre of stock solution.

The Edgar Hyman`s Microdol substitute formula is simply Ferrania R-33 with added salt.
Sodium hexametaphosphate would be a good substitute for sodium tripolyphosphate as a sequestering agent.

 

[Ian Grant]

As Ron (PE) says the Sodium Tri-polyphosphate is irrelevant in the actual mechanics of the formulae, it's in other Ilford developers and those from other companies purely as a sequestering agent to help with hard water.

Whether anything else is added we can't tell easily, but the developer as in #15 doesn't suffer from Dichroic fogging with Ilford films, (without the Tripolyphosphate).

As to Ferrania R-33 most pre 70's Kodak B&W developers were similar to or sometimes derived from other companies formulae, every company did the same some copied Kodak to. There's only so many permutations of the handful of common developing agents etc that were in typical use until more esoteric developers began appearing in the 70's.

Anyone looking at the evolution & time-scale of Kodak Developer formulae would be very surprised at just how long it took to get from the Wellington & Ward Buffered Borax Developer & D76 to D23/D25, and DK20, particularly when you actually look at the formulae

Ian

 

[Photo Engineer]

Well, I know for a fact that there is an additional ingredient and this from the source, Dick Henn. I just don't know the Microdol or Microdol-X formulas, but I know that the ingredient(s) are patented. I suspect only one is used, but I do not rule out more than one.

I found a note to this effect in my personal log book after a loooong search, but not the formula.

PE

 

[Keith Tapscott.]

Well, I know for a fact that there is an additional ingredient and this from the source, Dick Henn. I just don't know the Microdol or Microdol-X formulas, but I know that the ingredient(s) are patented. I suspect only one is used, but I do not rule out more than one.

I found a note to this effect in my personal log book after a loooong search, but not the formula.

PE

Without making empirical test comparing Microdol-X with Ilford Perceptol and the Edgar Hyman formula as published, it is difficult to know if Microdol-X with it`s alleged secret ingredient(s) offers any real benefits to the other two developers.
Such a test is beyond the capabilities of most people here.

 

[Ian Grant]

I didn't realise Henn worked on Perceptol

Having read all of Henn's Patent's we could probably easily find an additive which would have worked well with the films of that era.

A huge advantage today is that modern emulsions have changed and evolved and are now far less prone to Dichroic fogging, which is why many older formulae have come back into use.

I tested DK-20 supposedly the worst for Dichroic fog back in the late 70's and never had it with Ilford films, I was testing Monobaths to and some had it so was well aware of the issues.

Ian

 

[Ian Grant]

Without making empirical test comparing Microdol-X with Ilford Perceptol and the Edgar Hyman formula as published, it is difficult to know if Microdol-X with it`s alleged secret ingredient(s) offers any real benefits to the other two developers.
Such a test is beyond the capabilities of most people here.

My last post kind of answered your point.

Devs like DK-20 only caused problems with some films not all, but a company like Ilford or Kodak needed to sell products that worked, no excuse because the film type was wrong.

You can't test a film, fix, toner with every film/paper combination a manufacturer must ensure they work.

Ian

 

[Keith Tapscott.]

For processing sheet-films, Kodak recommend their T-Max RS developer, but not the standard non-replenishable T-Max developer which they say might cause dichroic fog. There are people on this forum who say that they use the latter for developing sheet-films without any signs of dichroic fog.
Back to the OP, if the Edgar Hyman formula matches Ilford`s own Perceptol developer with the very same times and dilutions, then it is worthwhile knowing that a suitable substitute is available if Ilford for some reason stop selling Perceptol in the near future.

 

[Keith Tapscott.]

My last post kind of answered your point.

Devs like DK-20 only caused problems with some films not all, but a company like Ilford or Kodak needed to sell products that worked, no excuse because the film type was wrong.

You can't test a film, fix, toner with every film/paper combination a manufacturer must ensure they work.

Ian

Perhaps it is better to design a developer for a specific film type rather than make a "one-size fits all films" type of developer.
Isn`t that what Geoffrey Crawley tried to do with his FX series?

 

[Photo Engineer]

Without making empirical test comparing Microdol-X with Ilford Perceptol and the Edgar Hyman formula as published, it is difficult to know if Microdol-X with it`s alleged secret ingredient(s) offers any real benefits to the other two developers.
Such a test is beyond the capabilities of most people here.

I cannot answer that either.

The most evident effect would be speed/grain/sharpness or maybe formation of dichroic fog.

PE