# Is bromide that important in home made developers ?



## timor (Jan 21, 2013)

So, that is the question brought here from another tread. 
I ask as there is a lot of formulas without this ingredient, some of the most famous developers don't have it.
Your opinions please.


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## unpopular (Jan 21, 2013)

According to Fundamentals of Photography by Paul E. Boucher, a restrainer is any chemical which slows down the effects of development. Bromide prevents development in areas lacking exposure (fog) by "tuning down" the developer. Bear in mind, this book is my primary source of specific information and was published in the 1940's, so it may not be 100% accurate; the entries about restrainer do have a certain chemical mystique about them.

Boucher also suggests that the restrainer is only necessary to facilitate fast for emulsions as they take longer to develop, this may explain why some historic formulary and many paper developers do not call for it. Other developing agents may also not be as naturally active as others. But I do not think that merely diluting a highly active developer is enough, while there is less developer "there" what is there is still very "active", and likewise simply adjusting pH doesn't seem to work, either. I'm guessing that while a restrained developer might take longer, it's less likely to fog - though all of this I am not 100% sure of.

So-called "cafenols" suffer exactly what you'd expect from an unrestrained developer. Although very dilute, the images tend to suffer from severe fog resulting from long development time. Ascorbic acid being a developer in itself will likely add to the problem since developers tend to be synergetic.


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## Ysarex (Jan 21, 2013)

Film developers or print developers?

I would frequently add bromide to print developers to extend the development time and thereby increase contrast especially with graded papers.

Joe


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## unpopular (Jan 21, 2013)

^^ I think this is the basic idea - extending developer to maximize contrast without fogging. I'm kind of wondering if what it does is keep the "hot" regions from going bananas to allow the less exposed regions to develop? 

Does that sound right, Ysarex? Kind of even out development time? I've never got into compounding print developers, so I never really saw what was going on.


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## compur (Jan 22, 2013)

Many developer formulas contain no bromide and are fine developers. The entire formula is what counts. A developer is more than the sum of its parts.


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## unpopular (Jan 22, 2013)

^^ i'm curious though what other restrainers might exist, can you point out which film developers would lack bromide?


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## unpopular (Jan 22, 2013)

I'm looking at Micodol X, which contains no bromide, but a significant amount of Sodium Chloride and Sodium Sulfite, as well as Boron trioxide. Sodium Sulfite is a preservative, I have no idea what all the salt is for, and Boron Trioxide, not to be confused with Sodium Borate, has a pH of 4.0, so I am guessing the sulfite is also acting as the accelerator?


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## compur (Jan 22, 2013)

unpopular said:


> ^^ i'm curious though what other restrainers might exist,



Potassium iodide, benzotriazole, pinacryptol yellow.



> can you point out which film developers would lack bromide?



D76, XTOL, Beutler, FX-1, FX-2, Windisch, PMK, D-23 and many others.

To quote Stephen Anchell's _The Film Developing Cookbook,_ 3rd Ed.:

&#8220;_Restrainers were once thought to be necessary in virtually all developers to reduce fog. It is now realized that restrainers usually impair image quality and are often only necessary to  correct too strong an alkali.  Hence [Grant] Haist's advice to reduce alkalinity instead of reaching for a restrainer.&#8221; _


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## unpopular (Jan 22, 2013)

^^ much better and more modern information! As I said, my primary source is out-dated, and unfortunately can't really recommend it anymore.

For some reason I thought D76 used bromide. But yeah, you're right. It's just hydroquinone, metol, sulfite and Kodak's friend, Boron trioxide, which appears to be anhydrous boric acid  - what is this for, any ideas? It's present in very small quantity.

ETA: I can't find anything special, I'm thinking it's a buffer.


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## compur (Jan 22, 2013)

Boric acid is a buffer.  Used to maintain pH when the developer is diluted. It's also used for stop baths and killing cockroaches.

Here is some info on your salt/Microdol question from the same source as above:

_"This was the discovery Henn published in 1944. He refined his approach in the commercial developer Kodak Microdol and its successor, Microdol-X. Although the formula for this proprietary, super-fine grain developer has never been published by Kodak, it consists of D-23 with the startlingly simple addition of a small amount of common salt. Salt has the ability to decrease graininess without the penalty of increased developing time. This is the homey secret behind Microdol and Microdol-X. Though it cannot be officially verified, a close approximation to the Microdol formula is 5 grams Metol, 100 grams sulfite, and 30 grams sodium chloride to a liter of water.
_
_"The increased solvent effect of developers with common salt is proportional to exposure, since salt primarily affects silver that has been exposed. Many other compounds have been studied for obtaining reduced graininess but no one seems to have found a better or simpler way of designing super-fine grain developers than Henn."  

_The above is from the 2nd edition of the book but is not in the 3rd edition. I'm guessing Kodak asked that it be removed?


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## unpopular (Jan 22, 2013)

It's not some giant secret, never was, at least not over the last decade. People go on like it is, but it's not. Every single formula, including concentrations are in the MSDS, published by Kodak directly.


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## compur (Jan 22, 2013)

True but I think it's the way it's worded in Anchell's quote above I'm guessing may have rubbed Kodak the wrong way:  "Microdol-X is just D23 plus salt"

It trivializes a Kodak product, especially since D23 is already widely known as probably the simplest of all developer formulas -- just 2 ingredients.

It's like saying that a famous restaurant's secret sauce is just mayo & ketchup. It kills the mystique, you know?


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## Helen B (Jan 22, 2013)

I've never seen the actual concentration given on an MSDS - they usually just give a range of values, which is not enough information to make the developer from scratch. They may also omit some ingredients in some circumstances.


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## unpopular (Jan 22, 2013)

well, if you want an exact duplicate then you should buy it from the store, though that isn't really the point. but I do think that compur is right, there is an unwarranted mystique to developers, these formulas aren't like precise drugs or anything and the rxn is usually pretty forgiving.


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## compur (Jan 22, 2013)

Helen's right.  You can't really duplicate the formula from the MSDS because the proportions are not accurate enough and varying proportions can produce changes in developer characteristics.

And, as for mystique -- in order to really see how changes in formulas can affect a negative we'd have to take the same photo with the same film and lighting and the same camera & settings over and over and use different developers on each for comparison -- something photographers rarely do. I know I don't anyway.


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## unpopular (Jan 22, 2013)

I don't really think anyone who is interested compounding formula is interested in exactly replicating existing developers. I know that if I start with the D76 ranges and add more hydroquinone I'll get grainier, sharper results. If I add more metol I'll get softer, smoother results. If I increase the pH it will develop faster, less, develop slower.

Sure, I could expose a step wedge (no need for exact lighting, just use an enlarger with an incident meter or probe) and measure exactly the development time at varied proportions of different developers at different pH and use a microdensitometer to measure accutance, granularity and gamma, I'd then have a whole host of detailed analysis of what variables do what - and I'd have a blast doing it, too, just because I'm into sensitometry (if that's not geeky, I don't know what isn't) - but in practice I'm not sure what this would really accomplish. So long as you know what to do to address different concerns and the finished formulary is replicated, you should expect relatively predictable and similar results.


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## compur (Jan 22, 2013)

Myself, I don't alter formulas or packaged developers.  If I want something different I just pick another.


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## unpopular (Jan 22, 2013)

At least try splitting the developer!! Try developing hilights in microdal and the shadows in dilute rodinal, with a water stop in between. You'll get the smooth long hilights of microdal without the blotchy, low accutance shadows, and the tight sharp grain of rodinal without the salt and pepper in the hilights: best of both worlds!

This combination was my favorite.


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## compur (Jan 22, 2013)

Noted -- thanks.


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