Sanity Check Please . . . regarding Developer Ratios

John Galt · Mar 19, 2018

I am getting ready to develop some FP4+ shot at box speed with Microdol X. And me, being an engineer started overthinking things again . . . it's a curse :/

I wish to use 1:3 ratio for the Microdol X. My question is this . . . is 1:3 = one part stock solution PLUS 3 parts water, i.e. a 25% solution . . .

. . . OR is it a 33% solution, i.e. 33% stock solution plus 66% water?

Like I said, sanity check please. My inner engineer is steering me toward the latter. One part stock plus two parts water = 1:3

Kawaiithulhu · Mar 19, 2018

This is why some instructions spell this out as 1+3 instead of the usual chemist 1:3
It's definitely not a ratio like 1/3.

John Galt · Mar 19, 2018

Thanks Guys . . it was the nomenclature that was stumbling me. 1+3 makes a lot more sense than 1:3. THANKS!!!

CMoore · Mar 19, 2018

I guess i never knew what the : meant.
I thought 1:3 was a ratio.?
For every
(1) of ABC
you need
(3) of XYZ
Is that not what 1:3 means.?

voceumana · Mar 19, 2018

1:3 is a ratio, but the question becomes "a ratio of what to what"? Is it 1 part of A to 3 parts total (a 33% solution) or 1 part of A to 3 parts of B (a 25% solution); for photographic purposes it is always the latter. 1+3 is a more definitive statement of the ratio.
The ":" means "to".

CMoore · Mar 19, 2018

Then let me ask this..... 1:1
How would you guys read read that.?
and so then..... 1:2.....1:3
I have never seen it interpreted the way you guys are saying.
But then i was just blue collar schlub in The Painters Union.
We were often referred to as "less than bright"

MattKing · Mar 19, 2018

Most commonly you will encounter the "1:1" nomenclature in Kodak materials.
As indicated above, it is used to indicate the ratio of stock concentrate to diluting water.
I prefer the 1+1 nomenclature, but after decades of using Kodak materials, I don't find it confusing.
What I do find confusing is where is the OP getting current instructions for Microdol-X?

Sirius Glass · Mar 19, 2018

michael_r said:
1 part stock plus 3 parts water.

+1

Kawaiithulhu said:
This is why some instructions spell this out as 1+3 instead of the usual chemist 1:3
It's definitely not a ratio like 1/3.

Tradition

PhxMedFormatPhotog · Mar 19, 2018

MattKing said:
What I do find confusing is where is the OP getting current instructions for Microdol-X?

And where is he getting Microdol-X???

Sal Santamaura · Mar 20, 2018

CMoore said:
...
I thought 1:3 was a ratio.?
For every
(1) of ABC
you need
(3) of XYZ
Is that not what 1:3 means.?

Yes, it is a ratio. Yes, that's what it means. There should be no confusion. However, since this is photography, an incessant compulsion to complicate simple things results in continuous overlooking of and perversion of the obvious.

"One part stock to three parts water."

"One part stock plus three parts water."

Two unambiguous ways of saying the same thing. Pretty simple.

darkroommike · Mar 20, 2018

Kodak is not 1 in three it is 1 to three, a proportion not a conventional ratio. Mathematicians have fits with this but chemists are OK with it, so I don't know. This discussion is over 100 years old. Using a proportion rather than a ratio as Kodak intended D-76 1:1 would just be stock D-76 and THAT makes no sense.

Arklatexian · Mar 20, 2018

Sal Santamaura said:
Yes, it is a ratio. Yes, that's what it means. There should be no confusion. However, since this is photography, an incessant compulsion to complicate simple things results in continuous overlooking of and perversion of the obvious.

"One part stock to three parts water."

"One part stock plus three parts water."

Two unambiguous ways of saying the same thing. Pretty simple.

+1

Ian Grant · Mar 21, 2018

Alessandro Serrao said:
1:3 = 1 stock solution in 3 parts total
1+3 = 1 stock solution in 3 parts water

Correct, unfortunately Kodak use the term 1:3 incorrectly.

Ian

John Galt · Mar 21, 2018

PhxMedFormatPhotog said:
And where is he getting Microdol-X???

I have several old cans that I got an an auction . . .

removed account4 · Mar 21, 2018

CMoore said:
Then let me ask this..... 1:1
How would you guys read read that.?
and so then..... 1:2.....1:3
I have never seen it interpreted the way you guys are saying.
But then i was just blue collar schlub in The Painters Union.
We were often referred to as "less than bright"

its funny, it wasn't until i got a usership to APUG in 2003 that i ever heard it was different than 1:1 being 1 part mixed with 1 part or 1 part mixed with 2 parts ( 1:2 ) or 1 part mixed with 3 parts ( 1:3)
no clue why people add the components together .. before "here" ive never saw it with a "+" instead of a : ...

thank you mrs T..

Ian Grant · Mar 22, 2018

Many years ago one manufacturer, I think Johnsons of Hendon, would use both - so say dilutions of a developer were1:10 and 1:15 or 1:20 then for clarity add the 1+9, 1+14. 1+19 in brackets I think in smaller print immediately after.

Ian

PhxMedFormatPhotog · Mar 22, 2018

Ian Grant said:
Many years ago one manufacturer, I think Johnsons of Hendon, would use both - so say dilutions of a developer were1:10 and 1:15 or 1:20 then for clarity add the 1+9, 1+14. 1+19 in brackets I think in smaller print immediately after.

But just to be clear, 1:10 = 1+10, not 1+9.

Ian Grant · Mar 22, 2018

PhxMedFormatPhotog said:
But just to be clear, 1:10 = 1+10, not 1+9.

Totally incorrect 1:10 is a ratio and made up by adding 1 part to 9 parts so 1+9, the fact that Eastman Kodak use the wrong term is irrelevant except for their products. Percetol the Ilford equivalent of Microdol-X uses the term 1+3, and Kodak Ltd (UK/Europe) always said 1 part plus 3 parts so 1+3, they never used the ratio.

Ian

Sirius Glass · Mar 22, 2018

PhxMedFormatPhotog said:
But just to be clear, 1:10 = 1+10, not 1+9.

Ian Grant said:
Totally incorrect 1:10 is a ratio and made up by adding 1 part to 9 parts so 1+9, the fact that Eastman Kodak use the wrong term is irrelevant except for their products. Percetol the Ilford equivalent of Microdol-X uses the term 1+3, and Kodak Ltd (UK/Europe) always said 1 part plus 3 parts so 1+3, they never used the ratio.

Ian

Ian, I believe that you are wrong. It is 1 to 10 as in 1 part to 10 part. What you are talking about is 1:9. Johnsons of Herndon was not following the convention used in chemistry for centuries.

CMoore · Mar 22, 2018

Ian Grant said:
Totally incorrect 1:10 is a ratio and made up by adding 1 part to 9 parts so 1+9, the fact that Eastman Kodak use the wrong term is irrelevant except for their products. Percetol the Ilford equivalent of Microdol-X uses the term 1+3, and Kodak Ltd (UK/Europe) always said 1 part plus 3 parts so 1+3, they never used the ratio.

Ian

.....then what does this mean.?
....1:1
What is your math for this.?

When i mix developer that is 1:9.....I get One Liter of product.
You are saying i should have 900 ml.?

PhxMedFormatPhotog · Mar 22, 2018

CMoore said:
.....then what does this mean.?
....1:1
What is your math for this.?

It means one part stock plus one part water.

NB23 · Mar 22, 2018

1:3 definitely means “1 into 3”, but then again wtf does “one into three” mean?

They should write 1+3.

PhxMedFormatPhotog · Mar 22, 2018

CMoore said:
.....then what does this mean.?
....1:1
What is your math for this.?

In other words, for D-76 1:1, if my tank requires 400ml, I use 200ml of D-76 stock and 200ml of water; equal parts of both.

Ian Grant · Mar 22, 2018

Sirius Glass said:
Ian, I believe that you are wrong. It is 1 to 10 as in 1 part to 10 part. What you are talking about is 1:9. Johnsons of Herndon was not following the convention used in chemistry for centuries.

Look up what a Ratio means: A 1:10 ratio is a 10% dilution, 1:1000 a 0.1% dilution. 1 to 10 means take one part and water to dilute to 10 that's the ratio, the term "to" doesn't mean plus "+" it means the ratio also denoted as ":".

Kodak Ltd were always very clear, for instance: Take 1 part A, I part B, 1part C, and 7 parts water Kodak D1, that's 1+1+1+7 = 10 parts in total.

CMoore said:
.....then what does this mean.?
....1:1
What is your math for this.?

The problem is mathematics is plural, so it's maths, there's more than one number

Only Eastman Kodak incorrectly use the term 1:1 others use F.S. for full strength. Kodak incorrectly us the colon : instead of the plus + sign. Their inherent mistake in Chemical instructions wasn't there in their Research papers etc. This is what causes the confusion.

Ian

Sirius Glass · Mar 22, 2018

Ian Grant said:
Look up what a Ratio means: A 1:10 ratio is a 10% dilution, 1:1000 a 0.1% dilution. 1 to 10 means take one part and water to dilute to 10 that's the ratio, the term "to" doesn't mean plus "+" it means the ratio also denoted as ":".

Kodak Ltd were always very clear, for instance: Take 1 part A, I part B, 1part C, and 7 parts water Kodak D1, that's 1+1+1+7 = 10 parts in total.

The problem is mathematics is plural, so it's maths, there's more than one number

Only Eastman Kodak incorrectly use the term 1:1 others use F.S. for full strength. Kodak incorrectly us the colon : instead of the plus + sign. Their inherent mistake in Chemical instructions wasn't there in their Research papers etc. This is what causes the confusion.

Ian

Then we agree!

Sanity Check Please . . . regarding Developer Ratios

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