Diluting developers

[venchka]

For the rookies in the crowd, myself at the head of the line, would someone explain the method of arriving at the following dilutions? Expressed in terms of volume of developer plus volume of water. Metric or Imperial or US. I am ambimeasurment. :D

1:1
1:2
1:3

Bonus points for brevity & simplicity.

Thanks!

[Walter Calahan]

1:1 means one part developer to one part water (whatever unit of measurement you want)
1:2 means one part developer to two parts water
1:3 means one part developer to three parts water

[percepts]

assume for this example that required total volume is 1000ml

1:1 means 1 of dev and 1 of water. so add 1+1 = 2.
divide 1000/2 = 500. so thats 500 of dev and 500 of water.

1:3 means 1 of dev and 3 of water. so add 1+3 = 4.

1000/4 = 250. So thats one lot of 250 for the dev and 3 lots of 250 for the water which equals 250 dev and 750 of water.

what do I win?

[Doremus Scudder]

Walter is correct for typical photo lab use.

You should know, however, that for professional chemists 1:3 means one part out of three total, not one part out of four total.

For this reason, the more accurate and less confusing 1+1, 1+2, 1+3 etc. is more commonly used to mean "one part developer to one part water," "one part developer to two parts water," etc. You will see most manufacturers of photo chemicals using this system, i.e., with the plus sign instead of the colon.

Good luck,

Doremus Scudder

[Renato Tonelli]

Walter is correct for typical photo lab use.

You should know, however, that for professional chemists 1:3 means one part out of three total, not one part out of four total.

For this reason, the more accurate and less confusing 1+1, 1+2, 1+3 etc. is more commonly used to mean "one part developer to one part water," "one part developer to two parts water," etc. You will see most manufacturers of photo chemicals using this system, i.e., with the plus sign instead of the colon.

Good luck,

Doremus Scudder

I wish this forum had been around twenty years ago to explain it to me.

[Jim C.]

You should know, however, that for professional chemists 1:3 means one part out of three total, not one part out of four total.


I didn't know that !
I always thought 1:3 was 1 part - X to 3 parts - X.

Now I need to revisit some materials that never worked based on
the manufacturers ratios.:o

[jim kitchen]

Dear Doremus,

How correct you are... :)

Ilford uses that dilution nomenclature on the inside of their film developer cartons.


jim k

[IanG]

I didn't know that !
I always thought 1:3 was 1 part - X to 3 parts - X.

Now I need to revisit some materials that never worked based on
the manufacturers ratios.:o

Technically that's correct, and in some cases that's what some manufacturers meant.

Typically something marked 1:100 or 1:1000 meant take one part and dilute to a total of 100 or 1000 with water.

So a developer could typically be dilute 1:20 which in practice is 1+19. In general most manufacturers now use the + sign to overcome confusion.

Ian

[venchka]

OK, so there are two correct answers, more or less. I have been using Kodak's intructions when mixing Xtol 1:3:


Verdünnter Entwickler
KODAK XTOL Entwickler kann für die Einmalentwicklung
im Verhältnis 1:1, 1:2 oder 1:3 mit Wasser
(Entwickler : Wasser) verdünnt werden. Verdünnt bietet
der Entwickler leicht erhöhte Filmempfindlichkeit,
bessere Schärfe und ein etwas feineres Korn.

My German is too rusty to translate the entire passage. However, I still seem to be clever enough to figure out that Entwickler is developer (Xtol) and Wasser is H2O. Using the above example, I mix 100ml Xtol with 300ml water to make 400ml of working solution. I adjust the numbers to match the tank and quantity of film that I am developing. I usually work with 800ml total in the Jobo tanks. My negatives don't seem to mind that I am not adhering to chemist's standards.

Thanks everyone!

[venchka]

ps:

Agfa was more specific and this is how I mix Rodinal:



RODINAL AND RODINAL SPECIAL PROCESS TIMES
DEVELOPER
RODINAL 1 + 25
RODINAL 1 + 50
RODINAL 1 + 100
RODINAL 1 + 100

[IanG]

Kodak actually say 1+1 in their English language literature (http://www.kodak.com/global/en/professional/support/techPubs/j109/j109.pdf), they no longer recommend 1+2 or 1+3

Ian

[venchka]

Ian,

I know that. I'm glad I can't read German!

Following your link, I came to this:


Using Diluted Developer
Choose the appropriate development time and
temperature table for starting-point recommendations for
specific films in small tanks, tray, and rotary tubes.
You can dilute XTOL Developer 1:1 with water
(developer:water) for one-shot (single-use) processing.
Dilution at 1:1 will provide slightly greater film speed,
enhanced sharpness and shadow detail, and slightly more
grain.
Use diluted developer only once. Do not replenish or
reuse diluted developer.

I guess Kodak thinks like I do.

[Ed Richards]

Thanks Doremus! I knew the photo directions seemed wrong, but I could not remember why - it was from my chemist days.

[venchka]

Perhaps Sandy King will join in and explain what he means when he says to dilute Pyrocat 1:1:100.

[pkphotog]

Perhaps Sandy King will join in and explain what he means when he says to dilute Pyrocat 1:1:1000.

The dilution is 1:1:100 for Pyrocat, so that means you put in 1 part of solution A and
1 part of solution B into 100 parts of water.

[Gem Singer]

I'm not Sandy King, but I can tell you that it means:

1 part solution A + 1 part solution B+ one hundred parts water.

To make one liter of working solution I mix 10 ml "A" + 10 ml "B" + 1000ml water.

So simple that even a cave man can do it (sorry Geico).

[venchka]

Thanks. I had one too many zeros. I fixed it.

I thought that would be correct. I wanted confirmation.

[IanG]

I'm not Sandy King, but I can tell you that it means:

1 part solution A + 1 part solution B+ one hundred parts water.

To make one liter of working solution I mix 10 ml "A" + 10 ml "B" + 1000ml water.

So simple that even a cave man can do it (sorry Geico).


You raise an interesting conundrum

OK I happen to use Pyrocat HD, I use 2 measures 1 for the 10mll Part A then Part B then a bigger one for the litres, as i wash the small one into the larger one I then top up to each whole litre.

So effectively I'm doing 10ml + 10mnl : 1litre or put accurately 10ml +10ml + 980ml. That's how many people I know worked with Rodinal as well 1+50, well 10ml made up to 500ml.

There's a very good reason the large measures aren't calibrated for 1-10ml increments.

Ian

[Gem Singer]

Hey Sandy we need you here!

[venchka]

Call me dumb, but when Agfa went to the trouble of writing 1 + 25, 1 + 50 or 1 + 100 on the label on the bottle, I took them at their word. 1 part Rodinal and X parts water. However, the differences are neglible. I think it's interesting that everyone works a bit different, but we all manage a printable negative. If my friend Lee were to describe his method of mixing and diluting D-76 everyone here would swear that it's impossible to do.