


Originally Posted by Craig Swensson
Okaaay, so what is the answer to the OP
The OP asked "I just wanted to know if there's a consensus among you fine people".
I think the answer is no!
Steve.

I just wanted to stirr up a little war, that's all . Watch out for my next topic, "Is digital better than analogue?"
Seriously though, thanks for the replies. Evidently, there is no consensus, so that's that.
And the sign said, "long haired freaky people need not apply"

There was no consensus the last time this was asked about a year ago either.
Cose as we can get is a slight preference for the x+y notation rather then the x:y for normal mixing instructions, and an understating that 1:1 may not mean any dilution at all to some folks, particularly chem majors who have previously encountered another iterpretaion.
We can also all probably agree that many Kodak publications use something like 1:3 to mean one part developer mixed with 3 parts water. and so can register this as a Kodiakian reference.
Charles MacDonald
aa508@ncf.ca
I still live just beyond the fringe in Stittsville

It has been fun. One thing, though, one does not usually pronounce the ":". So if I write "1:1", I will still say to students "one to one", which is, for example, short for one part Dektol to one part water. So it is never a problem when talking to students.
Even my written instructions on the wall in the developing room are written out as "one part Dektol to one part water"...as most would be totally confused to even know what the ":" means in any context! And I even write out 8 oz of Dektol to 8 oz water, because going from 1:1 to 8:8 is a stretch for some! One should see how their eyes glaze over when talking about fractions (when cutting window mats)!
At least with LF landscape, a bad day of photography can still be a good day of exercise.

Originally Posted by Photo Engineer
Strictly speaking 1:50 and 1+50 mean the same to me and to most chemists and technical people. Same goes for 1:49 and 1+49..
1:50 gives 51 parts and 1:49 gives 50 parts. It is normal to mix up to a given total such as 50 parts or 10 parts.
So, a 10% solution is 1:9 or 10 ml of A and 90 ml of B.
PE
As a chemist, I disagree.
1:50 is a ratio and it equals 1+49, which notes the parts used in preparing the solution.
Personally, I prefer the use of "dilution factor", which would be a "50 dilution factor" for the example I've just given above.
Kirk
For up from the ashes, up from the ashes, grow the roses of success!

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Originally Posted by Kirk Keyes
As a chemist, I disagree.
1:50 is a ratio and it equals 1+49
As a normal person, I disagree with your disagreement!
If 1:50 is a ratio (which is how I see it) I would think of it as one part to fifty parts. The difference is that I see the fifty parts as being of one thing, you see it as being the total.
I don't think there will ever be any agreement on this!
Steve.

Kirk, in the case you described, "1:50" is not a ratio. The way you use it must be called something else besides a ratio  a dilution factor or whatever you wish to call it..but not a ratio.
By the definition of a ratio (I checked out many online definitions), 1:50 means for every one of something there are 50 of another. But by what you are saying, chemists do not use 1:50 as a ratio, but as a symbol which means 1 in 50.
Thus if there is one boy and three girls, the ratio of boys to girls is 1:3 (or 1+3). The dilution of boys into the total group of people, by yours (and chemists you work with) use of the symbol ":", is 1:4  one boy in a group of 4 people. The ratio is not 1:4.
At least with LF landscape, a bad day of photography can still be a good day of exercise.

i think the only thing that matters is if someone is consistent in what they do
if they do 1 part and 49 parts or 1 part and 50 parts
and their results are to their liking, that is all that counts.

In fact i always prefer to go with "+" term than say ":", i take it as both are the same, but now i read this thread i see there may be different or the same.
Well, if i will ask questions about dilutions then i will ask you people with + not with :, i want to stay with one symbol and not be confused.
Why not using 1+50=51, so we know that it is 51 total not that it is 1:50=1+49 so the total is 50, this really will make nonsense for some people like me noob, i have one developer that has many dilutions options to use, so i can't be clear with + or :, I am not a chemist so i will not be so strict to some rules or symbols meanings.

Kirk;
Look at the reference I gave to the definition of "ratio". It is, as you say something like 1:50 but each number is a part, and neither is the whole.
PE

