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Why do we dilute? Full strength vs Dilution 1:1


+1
 
RalphLambrecht said:
+1
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This has been debated several times on APUG but
I still think for the person in charge of mixing,the instruction 1+1 is more clear than 1:1 and I find 1:0 especially confusing. 1 is the developer, now tell me how much water to add.with 1+0, I know to add none;with 1+1,I know to add the same amount,Hence,I prefer the '+'sign and not the ratio in mixing instructions.But,that's just me.
 
Bruce Osgood said:
1:1 is NO CHANGE, or stock, one to one. It is not one plus one.

1:2 is one plus one, or 1 to 2. It is not 1+2, never was.

The : is not a plus sign. It is a ratio sign.

The second number is the product of thr ratio.
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if 1:2 is one plus one then,why not write it that way?1+1;seems easier to meratio or not,Iprefer the clearer mixing instruction without having to calculate
 

I think,I need some wiskey,undiluted or neat
 

That's where 1:0 gets rather tricky,doesn't it?;ratios are inferior in mixing indtructions,clearlyI think,I need some wiskey,undiluted or neat
 

Pick up whatever solution you are comfortable with, who cares? No need to be harsh on me. When people debate on dilution ratio and how to express it, I guess it is normal to try to find an appropriate answer. Now if the Wikipedia page is not clear enough, feel free to amend it.
 

A fraction, say "1/2", can be read in context here for example as "1/2 of 250ml" meaning "125ml of stock and 125ml of water". A fraction defines "a portion of the whole".

A ratio, say 1:1, can be read in context here for example as "125ml of stock and 125ml of water" or "125:125". A ratio defines "how much of each part"

The fraction "1/1" in context here says "250ml of 250ml"; the fraction "1/2" says "the developer is 125ml of the 250ml total volume".

The ratio "1:0" in context "one part developer and no water" i.e. "250:0"; "1:1" means "one part developer and/plus one part water" i.e. "125:125".
 
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Ralph,
You are absolutely right that 1 + 1 is much simpler and less confusing than 1:2 to the hobbyist. The professionals I've know would argue that ratios are not arithmetlic. Each is valid and has its' own discipline. The notion that the symbol : is the same as + is something Kodak came up with while they disolved into bankrupcy. It is Corporate America's dumbing down of the public to their level. Greed Creates Need.

That's my little rant for the day. Back to WHY DO WE DILUTE?
 
Bruce Osgood said:
That's my little rant for the day. Back to WHY DO WE DILUTE?
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Because people are afraid of trying replenishment, they think using these developers dilute is economic, it isn't. I began using replenishment when I was about 16 initially with Microphen/ID-68), it made sense saved me money and time as the working solution was always ready. Later I switched to ID-11 (D76) and eventually deep tanks.

The benefits of Replenishment are the developer is always ready it just needs temperature adjustment, it's extremely consistent, the negatives are higher quality once it's seasoned than FS or diluted 1+1 or 1+3 - finer grain, better acutance (sharpnes), better tonality, and it's extremely economic. It's also well tried and tested as it was the standard way of working in commercial labs.

Ian
 
there is the little matter of how much and how often you actually do development. Most people use very little film and dev so the economies to be had from replenishment are debateable, especially if you're not using the same developer all the time. Having litres and/or gallons of mixed stock lying around in a small darkroom isn't necessarily desirable when it takes you a month of sundays to use only a litre of stock.
 

If the amount being processed is low then a long lasting liquid developer is a far better idea.

Ian
 
OP here. The back of the D-76 packet specifies a certain development time for stock solution and a different development time for 1:1. I think the 1:1 has to the one part developer, one part water dilution.

Wikipedia:
"In mathematics, a ratio is a relationship between two numbers."
"In layman's terms a ratio represents, for every amount of one thing, how much there is of another thing."

Therefore, I'm concluding it is not a part-to-whole ratio, it's a part-to-part ratio. Ratios can be expressed either way.
 
+1

and the d76 datasheet from kodak says full strength with one time and then 1:1 with a longer time

No wonder people always seem to quote different times and dilutions. Lets hope this has finally wrapped this one up.
 

 
moodlover said:
Ratios can be expressed either way.
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Actually no, they are fundamentally different relationships.

Mathematic ratios show the relationship of various "parts" being "added together". The easiest way for me to understand a ratio is "as a recipe".

2/cups Bisquick+2/eggs+1/cup water=pancakes.

Fractions represent a part of a whole, "division".

For example I might say Bisquick is 2/cups of my breakfast or 3/5ths of my breakfast, but those fractions don't tell me much about the rest of my breakfast.
 
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mklw1954 said:
Kodak's D76 data sheet explains the effect of using the stock solution vs. using 1:1 (one part stock solution and one part water).
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moodlover said:
The back of the D-76 packet specifies a certain development time for stock solution and a different development time for 1:1. I think the 1:1 has to the one part developer, one part water dilution.
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+2
 
Ratio of 1A:1B means 1 of A and 1 of B

Proportion 1A:1B means 1A forms 1 part of B

They have very different meanings which is what is being argued here. Some are claiming the notation means proportion of and others (me included) are saying the notation is a ratio and thats what the manufacturers use. Has anyone ever heard or seen of any manufacturer describing the mixing as anything other than ratios or A plus B. I have never seen one using "Proportion" in the teminology they use.
 
There's confusion because Kodak refer to ratio rather than dilution and unless you state clearly what you mean by 1:3 there's ambiguity. In some publications Kodak do use the term ratio.

Other companies use very much clearer terms and this is why typical dilutions might be listed as 1:20 with instructions stating that's 1 part developer + 19 parts water.

So a Dilution of 1:20 is actually a Ratio of 1:19. This is also why dilutions are often 1 +9, +19. +29 etc

Kodak are very clear in the HC110 data-sheet that the 1:3, 1:29 etc etc are ratios, while in the data sheet for D76 j-78 they incorrectly state it can be Diluted 1:1 something that's a oxmoron as it means the starting volume is the same as the final volume and no dilution has occurred. Luckily most people realise what they mean. Whoever wrote some of the Kodak data-sheets began mistakenly calling Ratios dilutions.

Ian
 
Ian, I think you nailed it.
 

I use a 1.25 litre bottle of HC-110 dilution E working solution and I mix up 250 ml of replenisher at a time.

I use 15 ml of replenisher for each roll of film.

I do most of my development in Paterson tanks that take up to 1 litre of solution.

If and when I transition to X-Tol, I'll continue to use 1.25 litres of working solution, and up to 5 litres of replenisher in 1 litre bottles.

Not too bad when it comes to space.
 

That is correct. I was reluctant to try replenishment because the Kodak instructions were so terse that what was meant was not clear.

Kodak's and Ilford's dilution instructions are both unclear and confusing.
 
It seems D76 1:1 is a pretty popular method so I'll give it a try! Thanks everyone.
 
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