Developer mixing question

I'm trying to learn how to mix chemicals for my first attempt at developing 35mm B & W film. Impressed by the results of the combination of Rodinal and Xtol I struggle with the formulas. For example, 1:2 Xtol & 1:100 Rodinal. The liquid Rodinal is pretty straightforward, mix 1ml of Rodinal with 100ml water. Xtol, being in powder form is what confuses me. Do I mix my bag of dry Xtol with the 5 liters of water, per manufacturers direction and then further dilute this mix at a ratio of 1 part of the mixture to 2 parts of water?

Grampadoug said:

I'm trying to learn how to mix chemicals for my first attempt at developing 35mm B & W film. Impressed by the results of the combination of Rodinal and Xtol I struggle with the formulas. For example, 1:2 Xtol & 1:100 Rodinal. The liquid Rodinal is pretty straightforward, mix 1ml of Rodinal with 100ml water. Xtol, being in powder form is what confuses me. Do I mix my bag of dry Xtol with the 5 liters of water, per manufacturers direction and then further dilute this mix at a ratio of 1 part of the mixture to 2 parts of water?

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Welcome to APUG.

Strictly speaking, 1:100 means to dilute 1 part concentrate until the total volume is 100 parts. Sometimes (more clearly) expressed as 1 part concentrate plus 99 parts water, or 1+99. And then again, Kodak sometimes uses 1:1 to mean 1+1.

For X-Tol (or any other powdered chemicals), yes, you do have to mix up the entire package of powder to make 5 litres first. Be sure to follow the mixing instructions carefully, because they instruct you to add water until the final volume is 5 litres, which is slightly different than adding 5 litres water.

And as for diluting X-Tol, I would suggest starting out with the dilutions recommended by Kodak - either straight stock, or stock diluted 1+1 (shown as 1:1 on the Kodak datasheet).

Here is the link to that datasheet: http://www.kodak.com/global/en/professional/support/techPubs/j109/j109.pdf

Have fun!

Since you are new to BW development I would suggest using either Rodinal OR Xtol. People assume that mixing two developers will get them the best of each used separately Often what they achieve is the worst characteristics of the two. Developers are finely balanced mixtures. When you start tinkering with them you destroy the balance. Until you are completely familiar with a film and a developer it is best to avoid experimentation. Rather than trying to mix up a portion of the 5 liter Xtol package I would suggest HC-110 as an easy to use and dependable developer.It is a concentrate like Rodinal and ideal for someone would is not developing on a regular basis.

When using very low concentrations of developer as in your example 1:100 each developer needs a minimum amount of concentrate to properly develop film. There must be enough developing agent(s) present. This may require mixing up a greater volume of working solution than is just needed to cover the film. I believe Agfa recommended 7 ml of concentrate for each 80 in2 of film. Using less can cause a loss of contrast and mottling of the negatives.

Use XTOL straight or replenished. I use replenished XTOL for finer and more continuous grain.

Welcome to APUG!