MCM 100 film developer

[Paul Howell]

So D 76 and Rodinal, Dk 50, Pyro, Buetler are common and are older than MCM 100, what are modern developers?

 

[JW PHOTO]

So D 76 and Rodinal, Dk 50, Pyro, Buetler are common and are older than MCM 100, what are modern developers?

Good one Paul! That ought to get some heads scratched.

 

[Gerald C Koch]

I'm curious, what has changed with film that makes these developing agents less relevant?

Modern films are much finer grained than the ones available when MCM 100 was formulated. So the inclusion of a powerful silver halide solvent is not necessary. In fact with certain emulsions their use can result in dichroic fog. Modern films have better tonality, speed... Everything changed for the better.

 

[Gerald C Koch]

Good one Paul! That ought to get some heads scratched.

Modern developers containing a phenidone or a derivative like Domezone or replacing hydroquinone with ascorbic acid.

 

[Paul Howell]

So Rodinal, D76 are obsolete and we should only use Xtol or other similar formula? I have used Xtol, both the Kodak and Foma version, have used D76 in many versions, ANSCO, Ilford, Fuji, extensively in the past and none have the same characters as MCM or other PPD developers. Not to say that MCM is better, just different. In general I don't disagree with your take on modern vs legacy developers, and I am afraid that the once the EPA new rules are in place the Feds will be taking your point of view to heart. Then again, PPD is becoming very hard to get, the price of MCM 100 is up 50% over the last year or so. May well reach the point that I will using Xtol again.

 

[JW PHOTO]

Modern developers containing a phenidone or a derivative like Domezone or replacing hydroquinone with ascorbic acid.

Jerry,
I agree that phenidone and dimezone certainly helped in the film speed department, but are they really better than metol or even glycin? I have used a good portion of Pyrocat-HD and Pyrocat-MC and I prefer the MC(metol version) over the HD(phenidone version) and think it's a tad sharper. I guess it's all about trade offs.

 

[Gerald C Koch]

A metol based developer is going to be a tad sharper than a phenidone one. This is due to the fact that phenidone is not as sensitive to bromide buildup and its envolventment with edge effects is less striking.

I don't want this thread to decay into something like "my developer is better than your developer." I have stated two reasons why PPD is a poor choice for today's emulsions. Feel free to look up this developing agent in Haist, Mason, or Glakides. A "great" developer is not being withheld from the masses by the cognoscenti. It is situations like this when The Darkroom Cookbook and PF annoy me. They appear to give credence to the idea that these old developers are useful.

 

[Paul Howell]

A metol based developer is going to be a tad sharper than a phenidone one. This is due to the fact that phenidone is not as sensitive to bromide buildup and its envolventment with edge effects is less striking.

I don't want this thread to decay into something like "my developer is better than your developer." I have stated two reasons why PPD is a poor choice for today's emulsions. Feel free to look up this developing agent in Haist, Mason, or Glakides. A "great" developer is not being withheld from the masses by the cognoscenti. It is situations like this when The Darkroom Cookbook and PF annoy me. They appear to give credence to the idea that these old developers are useful.

These old developers are useful to me, MCM 100, Edwal 12, 20, and 777 provide a look that I find appealing. I don't think one developer is is more less useful than another, just different. Some take more work that others, some are more environmentally friendly that others, some more or less toxic, but all useful under the right circumstances.

 

[JW PHOTO]

These old developers are useful to me, MCM 100, Edwal 12, 20, and 777 provide a look that I find appealing. I don't think one developer is is more less useful than another, just different. Some take more work that others, some are more environmentally friendly that others, some more or less toxic, but all useful under the right circumstances.

I totally agree Paul and I'm rather fond of Edwal 12 myself. Is it better than Xtol or HC-110? Nope! But it gives a different look that's for sure. Whatever floats your boat I guess!

 

[Gerald C Koch]

There is a question that I like to put forward to those who cannot live without these old developer formulations. If they were so good why did they fall from favor? Why aren't they at least as popular as D-76 today?

 

[JW PHOTO]

There is a question that I like to put forward to those who cannot live without these old developer formulations. If they were so good why did they fall from favor? Why aren't they at least as popular as D-76 today?

Could be any number of things that wiped out many of these old brews Jerry. Keeping quality, ease of use, toxicity, availability, marketing, competition or probably just to darn many developers on the market for the amount of users. Many of these developers weren't even available to me when my, well supplied, local photo store was still in business. Now, it's a matter of hunting up a recipe and doing it yourself. Another good example would be printing papers. Kodak made some of, if not the best, photo printing paper. Where is it? Agfa, where is it? Does that mean just because it doesn't exist anymore that is was inferior to the new stuff? I absolutely loved Ilfords Cibachome/Ilfochrome printing materials, but can only dream now. I know that Cibachrome printing was the ultimate for me, but it doesn't exist so it couldn't have bee any good.
Jerry, I understand where you are coming from, but you have to understand where some of us are coming from, as to "our" tastes. Some people like coffee, some folks like tea! Both are good, but taste different.

 

[Gerald C Koch]

My questions were rhetorical designed to get people thinking.

Could be any number of things that wiped out many of these old brews Jerry. Keeping quality, ease of use, toxicity, availability, marketing, competition or probably just to darn many developers on the market for the amount of users. Many of these developers weren't even available to me when my, well supplied, local photo store was still in business. Now, it's a matter of hunting up a recipe and doing it yourself. Another good example would be printing papers. Kodak made some of, if not the best, photo printing paper. Where is it? Agfa, where is it? Does that mean just because it doesn't exist anymore that is was inferior to the new stuff? I absolutely loved Ilfords Cibachome/Ilfochrome printing materials, but can only dream now. I know that Cibachrome printing was the ultimate for me, but it doesn't exist so it couldn't have bee any good.
Jerry, I understand where you are coming from, but you have to understand where some of us are coming from, as to "our" tastes. Some people like coffee, some folks like tea! Both are good, but taste different.

My questions were rhetorical. But I am glad that some people are taking a closer and perhaps more discerning look at these old formulas.

 

[Gerald C Koch]

MCM-100 uses PPD in a superadditive combo with Catechol, so most of this doesn't apply to MCM-100.

This, on the other side, is quite relevant to MCM-100, and everyone should make a conscious decision whether some possible small pictorial improvements are worth the risk dealing with PPD. From what I read it goes right through skin, so the typical "well, I won't eat it then" precaution will not suffice.

The term super-additive is mentioned from time to time. The problem is that most people do not understand what the term means. It most definitely does not mean some magical combination of developing agents. All it really means is that a super-additive combination is faster acting than if the development time for each individual agent were considerd. Consider a developer containing two developing agents A and B. We can represent the development rates as rA and rB and the overall rate R as their sum. When there is no super-additivity then

R = rA + rB.

However when super-additivity is present

R > rA + rB.

Only the total development time has changed. NOTHING ELSE ABOUT THE DEVELOPMENT HAS CHANGED. The densitiy and contrast of the negatives is uneffected. The speed of the reaction was changed BUT not its outcome. Chemistry rules! Once again there is nothing magical about a super-additive combination.

 

[JPD]

There is a question that I like to put forward to those who cannot live without these old developer formulations. If they were so good why did they fall from favor? Why aren't they at least as popular as D-76 today?

Don't forget that the magic often is just an illusion in your head instead of reality. Mixing chemicals, developing, printing and looking at the photographs can for many people be likened to enjoying a symphony. Everything isn't science and based on logic. D-76 is excellent, but boring compared to Agfa 44 or Adox MQ. MCM 100 literally smells of photographic history with its obsolete components.

 

[Ian Grant]

The main company making B&W PPD based Meritol developers (coupled with Pyrocatechin) was Johnsons of Hendon in the UK. They were taken over in 1972 and the company asset stripped by the new owners ceasing chemical production in 1974.

A new company Phototechnology set up by their main chemist Pip Pippard continued with their colour chemistry and a limited B&W range.

I disagree with Gerald because many older developers work far better with modern T-grain and similar films than conventional emulsions. A good example is Rodinal with Tmax 100 where it gives much finer grain than D76, so I think there's still a need to try some of these older developers. I used some of the Johnsons Meritol based developers and they were excellent.

Ian

 

[Moopheus]

So Rodinal, D76 are obsolete and we should only use Xtol or other similar formula?

Rodinal has one useful attribute that warrants keeping a bottle around: the concentrate lasts for-freaking-ever. It will always be there for you, no matter how negligent you have been with your other chemicals.

 

[Rudeofus]

The term super-additive is mentioned from time to time. The problem is that most people do not understand what the term means.

I agree with this statement, since it is exemplified here in the following quote:

Only the total development time has changed. NOTHING ELSE ABOUT THE DEVELOPMENT HAS CHANGED. The densitiy and contrast of the negatives is uneffected. The speed of the reaction was changed BUT not its outcome. Chemistry rules! Once again there is nothing magical about a super-additive combination.

Many so called primary development agents are self restraining, i.e. they stick to silver and/or silver halide in their oxidized state and are only slowly scavenged (e.g. PPD and derivatives, Metol), or not at all (e.g. Phenidone). Most secondary development agents have very long induction times and develop only at very high pH, e.g. Catechol, Pyrogallol, Hydroquinone, Ascorbate and HQMS.

Used together in a superadditive combo they are a completely different animal, they develop at pH in which secondary development agent alone would be mostly inactive, and with very different pictorial properties in every respect. You can not explain the working of Xtol or DS-10 by simply extrapolating from POTA and a low pH Ascorbate only developer.

 

[Gerald C Koch]

Used together in a superadditive combo they are a completely different animal, they develop at pH in which secondary development agent alone would be mostly inactive, and with very different pictorial properties in every respect. You can not explain the working of Xtol or DS-10 by simply extrapolating from POTA and a low pH Ascorbate only developer.

I would respectfully disagree. I think a series of experiments could be devised to do this. Mason has a graph illustrating what happens as the molar ratio of a pair of super-additive developing agents is varied. There is an optimal ratio at which development is at its maximum rate. I have never seen any data concerning negative quality based on the ratio. If it were important then much research would have been spent in this area. The actual ratios are rather capricious and often vary from what is optimal usually for economic reason. Traditionally phenidone was more expensive than hydroquinone. The articles that I have ever read all stress the increase in development speed no other attribute.

Quoting on one definition of super-aditivity, "Of the two developing agents that are superadditive, the following is usually the case:

Agent 1 has lower reduction potential but much higher adsorption to the silver halide crystals.
Agent 2 has higher reduction potential but much poorer adsorption to the silver halide crystals.

Agent 1 is the developer that reduces the silver halide crystals. Oxidation product of Agent 1 is reduced back to the original form by Agent 2. In other words, the ultimate source of the electrons used to develop image comes from Agent 2. For this reason, in modern convention, Agent 1 is usually called electron transferring agent or ETA. Agent 2 is usually called the main developing agent.

As obvious from the above mechanism, developing agent with very stable semiquinone radical form (the first oxidized form of the ETA) tends to make more superadditive combination. Also obvious from the above mechanism is that Agent 1 has to have an intermediate reduction potential in the developer solution between the Fermi energy level of silver (the developing image silver) and the reduction potential of Agent 2 in the developer solution.

It is all about kinetics. The rate of development changes but not the ultimate product. It is still the same two developing agents with their reduction potentials creating a silver image.

 

[Gerald C Koch]

Let's consider a more classic combination since the chemistry of ascorbic acid is quite complex and oxidation adds to the complexity. As I have mentioned Mason provides a graph for a typical super-additive MQ developer. It shows the rate of development vs the molar ratio of metol to hydroquinone. The curve is roughly U shaped that bottom represents the optimal ratio of M:Q. A similar curve would occur for PQ developers, P:Q = 1:21 IIRC. As you get further and further away from the optimal point on either side the development time lengthens. Mason also mentions that these optimal ratios are seldom strictly adhered to because of economics.

As I have mentioned I have seen no reference to any other "special" property for a SA developer mixture. Neither In the texts that I have nor in others on the net. In fact Mason is a special case. Most texts just mention that a SA combination works more quickly or is vaguely more desirable or something to that effect. I might also mention that I have been through my books hundreds of times. If you look at the modern explanation of SA which I included in a post there is also nothing there. Perhaps Haist's books give more since they are the last word on modern photo theory. Literally the last word.

 

[Rudeofus]

As obvious from the above mechanism, developing agent with very stable semiquinone radical form (the first oxidized form of the ETA) tends to make more superadditive combination. Also obvious from the above mechanism is that Agent 1 has to have an intermediate reduction potential in the developer solution between the Fermi energy level of silver (the developing image silver) and the reduction potential of Agent 2 in the developer solution.

It is all about kinetics. The rate of development changes but not the ultimate product. It is still the same two developing agents with their reduction potentials creating a silver image.

This is definitely about a lot more than just kinetics, at least with Phenidone and its derivatives. While it is possible to create a Metol only version of D-76, there is no such thing as a Phenidone only counterpart to Microphen or Xtol, regardless of how long you develop.

I think that a lot of the discussion is strongly influenced by Metol and observation of Metol based developers, but Metol is not all that relevant in modern developers.

 

[Gerald C Koch]

There isn't really more that that in Haist.

Perhaps if nothing was written, I've come up with some new things (just kidding). In the experiments I ran with Dimezone-S, before I worked with ascorbates I used more traditional hydroxybenzenes (specifically HQ and pyrogallol). I got very similar macro-sensitometry to the later ascorbate experiments using the types of ratios I referred to above so perhaps Phenidones are the outlier when it comes to ratios only being about kinetics. For a commercial example of what I "came up with", Kodak's last version of Technidol use this type of mechanism to get very low overall contrast without massive losses in emulsion speed, using a Phenidone and HQ, likely in the kind of "reversed" ratio I experimented with.

I didn't experiment with metol in this case since it was really the wrong agent to start with for what I was going for. But even in the case of metol, I wonder if there's more than just kinetics when it comes to SA. I've thought of a few experiments but never did them.

There is an advantage in using metol as it is capable of producing an image of normal contrast when use alone. None of the phenidones will do this. Thus you can study just a metol developer, a hydroquinone developer and all combinations in between.

The phenidones are strongly bound to activation sites even in their oxidized state. This effectively switches off their developing activity and results in a very low contrast images. This is why they must be used with another developing agent like ascorbic acid or hydroqinone. Both ascorbic acid and hydroquinone have long induction periods. This is usually explained due to presence of a charged species. Hydroquinone forms the monosulfonate ion which is also a developing agent. Both however will develop if sufficient time elapses.

I am always reluctant to allow threads making some unsubstantiated magical claim to go unchallenged. I was beginning to hear the grail music from Parsifal and so I decided to get things on a more technical footing. As far as SA is concerned that is little beyond the explanation of development speed. As psychologists are said to remark "Sometimes a cigar is just a cigar."

 

[Paul Howell]

By the way, my original question: best way to replenish MCM 100? I have dumping a quart and adding a quart to a gallon of stock MCM 100 every 12 rolls of 35mm 36 ex or same square inches of MF and LF , my tank is now well over a year old. At point should I start a new tank? Saying this may be my last tank as a gallon of MCM 100 is now around $80.

 

[JW PHOTO]

By the way, my original question: best way to replenish MCM 100? I have dumping a quart and adding a quart to a gallon of stock MCM 100 every 12 rolls of 35mm 36 ex or same square inches of MF and LF , my tank is now well over a year old. At point should I start a new tank? Saying this may be my last tank as a gallon of MCM 100 is now around $80.

Well Paul, I think I'd dump my tank after I ran out of replenisher. If it were me? I'd also try mixing my own with Kodaks CD2 color developer component in place of PPD. I did this for my batch of Edwal 12 and it works just fine. Your new "homemade" MCM 100 will be much less than $80.00 to boot. You might want to do this while you still have your batch of MCM 100 so you can compare your home-brew to the MCM 100 you are using now. I would have to look at my notes, but I think I ran the CD2 at double what the Edwal 12 called for for PPD. Of course all this is meaningless if you want to just switch to one of the new "WONDER" developers.

 

[Paul Howell]

I might give your version a try. Do you standard color developer our just the color component? If it is the color component where do your source it?

 

[Gerald C Koch]

Traditionally commercial processors would periodically run a test strip through their tank and check. You could determine whether some replenishment was needed or whether it was time for a fresh tank. While it would be better to have a densitometer it is also something that can be eyeballed.

CD-2 is better than PPD as far as not causing reactions but it is still not without problems. In fact my dermatitis was caused by it and not PPD. However the end result was the sane. I have been sensitized and cannot process my own color film or use PPD in any form. Fortunately I was not cross-sensitized to metol and can still do B&W printing.

I was looking in my copy of Dr Lowe's book "What You Want To Know About Developers." No replenisher is specified and development times are increased after the first few rolls to compensate. So you are essentially stuck with self replenishment.