Rodinal 1:50 By Weight

Pieter12

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Plus a scale is something that can get dirty son collect dust and chemicals, takes up more space in the darkroom, go out of calibration, etc. I small graduated cylinder is not that hard to us
So one 35mm film in stand development requires a litre of solution. Does this mean that if you want to do say, 3 x135 films at once you need a 3L tank? Is there a Agfa Rodinal source for this that you can refer me to?

Thanks

pentaxuser
I cannot locate the Agfa data sheet where I had read that info. Adox states to use at least 5ml per roll of film, 5ml for 4 sheets of 4x5.
 

pentaxuser

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I cannot locate the Agfa data sheet where I had read that info. Adox states to use at least 5ml per roll of film, 5ml for 4 sheets of 4x5.
View attachment 266733

Thanks, I Iooked at my old Agfa Rodinal(the genuine Agfa Rodinal ) sheet and could find no mention of any min quantity but Ed Buffalo in his article "Appreciating Rodinal" does actually say that Agfa's recommendation is min 10ml but doesn't give a source for this However he goes on to say that he has found that 5ml is fine as Adox states

Mind you, the same Agfa instructions that I have state that once opened a bottle is good for at least 6 months. Now if that is not an understatement, I don't know what is I used my Rodinal the other week and from opening it has lasted now about 196 months

pentaxuser
 

john_s

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From an Agfa pdf on film developers (1999):

"Yield
One-shot developer.
With 500 ml concentrate about fifty films (135-36 or 120 rollfilm)
can be developed."

which could be read to mean 10mL per film.

And yes, I know that less also works.
 

Murray Kelly

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Scales that will accurately measure 500g to even as good as 1% are pricey. I'd fill it to 500 as best you can, suck out 10ml with a syringe, discard that and suck up the 10ml of Rodinal and mix. Normal usage is for 1+49.
Measuring exactly 500g (ml) is your problem not the Rodinal.
 
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OP

RoboRepublic

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First, it is 1+50, not 1:50 and I believe Agfa recommended a minimum of 10ml for each roll of film being developed.
For my edification, could you please help me understand the difference between the '+' and the ':' ?


Donald, interesting idea to decant into smaller vials; I'm not sure why I'm so resistant to syringes. Possibly because its one more item that needs thorough cleaning. I'll get a highquality one and see if my experience over last time (using a 200ml syringe for ddx 1:4/1+4) is better.

Over the years I've tried just about everything to measure small amounts of Rodinal. This 10mm dropper is the best I've found so far:
CLICK HERE
Brian P

Thanks Brian, I'll give this a shot.


If I understand correctly, it is the volume of the water that is the issue - he wants to make up the Rodinal without using his 500mL volumetric flask - or any other measure of volume once he knows the equivalent weights.

Sort of, measuring out 490ml using a volumetric flask, then measuring out 10ml using a syringe, or a skinny flask, is one more item in the dark room. The rodinal is especially a pain, since the quantity is very small.


Doremus, you have the right idea; However to use the daylight tank as mixing vessel would mean, chiefly, that I cannot load it with film in my dark bag The idea is to be precise, and convenient in space. A scratch would work, but in knowing myself I'd be paranoid that I over shot or undershot the scratch mark, much the same way as I try and read the meniscus on a beaker.
 

MattKing

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For my edification, could you please help me understand the difference between the '+' and the ':' ?
Historically, Kodak frequently used 1:49 in the same way as I and many others use 1+49.
Many chemists will tell you that Kodak should have used 1:50 instead (1 part amongst 50 in total).
It becomes more strange when you see something like 1:1 in a Kodak document.
There are heated arguments about this in a number of places here and otherwise on the internet.
 
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