D76 Chemistry question

[Ian Grant]

This one's been discussed a few times:

Agreed. In discussing ratios: 1 to 1, is 1:1, is equal volumes, is 1 part A and one part b, is 1+1. 1:0 is what it says it is.

In general 1:100 was traditionally always taken to be 1 part diluted to 100 or 1+99. or put more simply there's 1 part of chemical in 100 parts of final dilute solution. Unfortunately some small Photo companies started using 1:2.1:10 etc for dev & fix dilution which was ambiguous.

Ilford dilutions are usually 1+4, 1+9, 1+19 etc following a logical 5, 10, 20 ratios.

In practice most of us use developers like Rodinal at1:50 rather than 1+50 starting with say 20ml dev and diluting tat to a litre, effectively actually giving 1+49 and I suspect most do the same with devs like Pyrocat HD taking 10ml A, 10ml B and making up to 1 iltre with water, so although written as 1+1+100 in practice its actually 1+1+98, after all how many of us use accurate measure that will read 1020ml

Ian

 

[clayne]

The ratio crud only comes in to play depending on what one is measuring the ratio OF.

For instance, ratio of developer amount to OVERALL amount (USELESS).
vs.
Ratio of developer amount to water amount (USEFUL).

Really, the first one I find to be totally useless and who really needs that measurement when we're always dealing with water? It's of no benefit to me or anyone else to have a ratio delivered as A:A+B. It's many times more intuitive to have it stated as A:B, that is A vs. B. Why the former got any use whatsoever in photography is a mystery to me, but I firmly support people dropping it's use altogether. The '+' sign was no doubt repurposed to convey A vs B (where B is almost always water) due to the ambiguity created earlier.

 

[rternbach]

...To mix your own chemicals is easy, you only require a set of scales, a stirring rod and some washable plastic beakers, and then you’re off. You also require some stock of chemicals!...

Mick, thanks for your expertise. Which chemicals go into your D76? I have read different descriptions of the formula.

Best,

Rudy

 

[clayne]

http://silvergrain.org/Photo-Tech/d-76.html

 

[rternbach]

http://silvergrain.org/Photo-Tech/d-76.html

clayne,

Thanks for the url. It's great that there's so much information available on D76.

Best,

Rudy

 

[Keith Tapscott.]

Mick, thanks for your expertise. Which chemicals go into your D76? I have read different descriptions of the formula.

Best,

Rudy

I`m not Mick, but the basic formula for Kodak D-76 (also known as Ilford ID-11) has been published for many decades. You can easily make as little as half a litre of stock solution at a time. This can then be used quite quickly without too much unused solution going off on the shelf of your darkroom.

Measure 400ml of water at about 40*C and dissolve the following components.

Metol developing agent = 1 gram
Sodium sulphite, anhydrous = 50 grams
Hydroquinone = 2.5 grams
Borax = 1 gram
Add more water to make 500ml of stock solution.

Start with a `pinch` of the `weighed` sulphite first and then dissolve each component in the order listed above, ensuring that each one is fully dissolved before adding the next component.

 

[clayne]

Make sure to throw a powder mix of Tang or Kool-Aid into your solution to give it that extra ZING!

 

[dancqu]

The 1:1 as a ratio has become accepted to mean 1+1.

One TO one, 1:1. One part a TO one part b. A ratio.
In this case the ratio of two to be mixed components.
Other than 1+1 = 2, 1+1 has no other meaning. Dan

 

[clayne]

1 part + 1 part. It's well established what the convention means. The resultant is a ratio, yes. As long as the ratio is part A _TO_ part _B_ then they're the same. The second anyone brings up "B == entire solution" the whole thing gets thrown off.

The + part is used these days because there's no ambiguity that it indicates A:B whereas ":" could be taken to mean A:B or A:A+B depending on who you're talking to.

I'd love for everyone to just use a ratio, but then we might be back to A:A+B which I don't love.

 

[wogster]

The ratio crud only comes in to play depending on what one is measuring the ratio OF.

For instance, ratio of developer amount to OVERALL amount (USELESS).
vs.
Ratio of developer amount to water amount (USEFUL).

Really, the first one I find to be totally useless and who really needs that measurement when we're always dealing with water? It's of no benefit to me or anyone else to have a ratio delivered as A:A+B. It's many times more intuitive to have it stated as A:B, that is A vs. B. Why the former got any use whatsoever in photography is a mystery to me, but I firmly support people dropping it's use altogether. The '+' sign was no doubt repurposed to convey A vs B (where B is almost always water) due to the ambiguity created earlier.

Actually both ratios can be useful.

1:10 meaning for 300ml of developer you need 30ml of stock and the rest water, makes perfect sense. But then so does 1+9 meaning you need 30ml of stock and 270ml of water. The problem is that some instructions say 1:9 when they mean 1+9 so it gets confusing, and I have seen where the same company will use 1:9 in one set of instructions and 1+9 in another.

I think that 1:10 is more useful in American measure, where you have 16oz total, and can subdivide that, 10/16ths or 5/8 oz, where as 1+9 where you need to figure out what 5/8oz is multiplied by 9 times, means more complex math. In metric where it's shifting a decimal point around it's much easier, either way.

 

[Mick Fagan]

Rudy, and others, I’m not very expert at this chemistry business; I’ve just been fiddling at the edges for quite a few years. Firstly, so I could get developers, secondly, because mixing them yourself was generally cheaper 40 odd years ago.

In the late sixties for nearly two years I was living on a motorcycle in the day and in a tent in the night. I also had six aluminium screw top canisters with chemicals for photography, interestingly today, I still have those same six chemicals as my basic kit.

With these six chemicals, you can mix up a surprising array of film and paper developers. I first learnt about these chemicals from the old pharmacist, in his chemist shop, where I first purchased some chemicals for photography.

These are the chemicals:-

Metol
Sodium Sulphite
Hydroquinone
Borax
Sodium Carbonate
Potassium Bromide

D76/ID11 you have read the ingredients in an earlier posting on this thread.

Today I decided to print a portrait I took a couple of months ago of a friend, I mixed up a warm tone developer especially for this.

I used:-

Metol
Sodium Sulphite
Hydroquinone
Sodium Carbonate
Potassium Bromide

The developer is called ANSCO 135 and is a general warm tone developer.

Fine you say, one can pop into your local photo shop and pick up some Ilford Warm Tone paper developer, yes you sure can, but what if you wish to fiddle with it a bit. Not really an option.

By adding a bit more bromide I can make the warm tone bit a little stronger. I do this because I’m using Ilford MGIV RC pearl paper, it is a paper that doesn’t warm too much, but when I fiddle with it, I am able to get a warmth I’m very happy with.

Hopefully my friend likes his portrait as much as I do, we’ll see!

Regarding the bit mentioned before by Keith about adding a pinch of Sodium Sulphite before you add the metol, ummm, I’ve never done that.

I have read about this adding a pinch of this, before adding this chemical, many times. Unfortunately, having never really been in a position where I had a clean bench, let alone a darkroom for years, and, never really having copious notes as paper gets wet on a motorcycle and plastic bags weren’t really around back then, I just plopped the chemicals in, stirred until they looked as though they were all absorbed, then added the next chemical, and so on.

That doesn’t mean I’m correct, or perhaps technically incorrect, it’s just that this method works for me.

Trust me when I say, get yourself a basic B&W store of chemicals, a set of scales, a stirring rod, some beakers and you will not believe just how much fun you can have for so little money.

By the way a quad beam scale, never needs a battery and will always work, Paterson make a neat super cheap stirring rod. Purchase a funnel and a packet of the cheapest coffee filters to filter the precipitate out, which often gathers over time in your stock solutions.

Mick.

 

[rternbach]

Mick,

Thanks again for the information and the bit of lifestory that goes with it. I will take your approach to developing film as a model but not the motorcycle--swore them off many years ago--too many blind automobile drivers.

Cheers,

Rudy

 

[dancqu]

With these six chemicals, you can mix up
a surprising array ... These are the chemicals:

Metol
Sodium Sulfite
Hydroquinone
Borax
Sodium Carbonate
Potassium Bromide

Today .... I mixed up a warm tone developer
especially for this. I used:-

Metol
Sodium Sulphite
Hydroquinone
Sodium Carbonate
Potassium Bromide

The developer is called ANSCO 135 and is
a general warm tone developer.

By the way a quad beam scale, never needs
a battery and will always work, ... Mick.

A VERY basic kit will have metol, sulfite, carbonate,
and bromide. Use the first two for D-23, and the four
for Ansco 120; a film developer and the second a paper
developer. For additional contrast with carbonated
developers add hydroquinone. I'd skip the borax.
It's for those who can't live without their D-76.

A word or two regarding scales: A beam balance was
my way of weighing chemicals. Several years ago
I went digital and am not the least bit sorry.
They are a real step forward in speed
and convenience.

Mostly I mix partial batches which are meant for
immediate or soon use. I find my 0.01 gram
Acculab very adequate. Great capacity is
not needed. Dan

 

[cmacd123]

Interesting the different interpretations, to me 1:1 is one part a and one part b, 1:50 is one part a and 50 parts B. the first would normally yield 2 parts and the second 51 parts. with the high dilution stuff like the agfa classic, I end up with 255 Ml to fill my one 35mm roll stainless tank, (5 ml dev concentrate plus 5*50 Water)

 

[dancqu]

Interesting the different interpretations, to me 1:1 is one
part a and one part b, 1:50 is one part a and 50 parts B.

Or, how about to one cup of flour add one cup of water.
Add, +, kitchen talk. Ratio, this to that, this:that,
Lab talk. Dan

 

[Keith Tapscott.]

I'd skip the borax.
It's for those who can't live without their D-76.
Dan

I guess I fall into that category, I prefer D-76 to D-23.

 

[EASmithV]

I always use my D-76 fill strength, because with light use it has lasted oer 2 years (and counting). 1:1 can give you finer grain, but personally I prefer you stick to stock, the grain is not very heavy but not very fine, but can also look beautiful, if you are that kind of person .

To make 1:1 you take an equal amount of straight diluted D:76 (stock) and mix it with an equal amount of water (ie, 1L D76 Stock + 1L H2O = 2L D76 1:1). Like all dilutions, you will need to extend the time. Most dev times are well published for D76, both stock and 1:1.

easy