Figuring dilution

[Ulophot]

Ah! Dilution factor. You're probably right. Thank you, and thank you for the math as well. Very helpful.

[Doremus Scudder]

Philip,

To address the split-toning issue: I have taken to developing my negatives a bit less to end up printing at a rather high contrast setting lately, e.g., aiming for around 75M as "Normal" with MG Classic and other VC papers. This means I end up using less of the green-sensitive emulsion component in the paper and predominantly the blue-sensitive component(s). This seems to help with split toning. I believe that the grain size in the final print is more consistent this way, which would explain why it tones a bit better.

Still, when I have to burn large areas at a low contrast setting or really need that "grade 2" filtration, I'm careful when toning, pulling the print well before split toning becomes objectionable.

I'd love to see your results about the effects of dilution ratio on split-toning when you've finished testing. Do post!

And, sharktooth's method for arriving at a new dilution ratio is easier than what I posted for part-to-part dilutions (e.g., 1+19 = 20 parts total). The method I posted works really well for figuring percentage solutions, but with part-to-part dilutions adds the extra step of converting to percentage first.

Best,

Doremus

[Kevin Crisp]

Maybe I can simplify it even more. Let’s say you want selenium toner, rather dilute, at 1:40 like it says on the bottle. Also knownas 1-40 or 1.40 or whatever. I think 1:40 is the clear way to express it.

1. Add the 1 and the 40, which gives you 41. Hold that thought. We’re going to use that number in a second.

2. How much working solution do you want? Let’s say half a gallon or 64 oz.

3. Divide 64 by 41, and you get 1.56.

4. Pour 1.5 (or 1.6) oz of the concentrated toner into a bottle. Depends which way you want to round 1.56. It won’t make any difference.

5. Fill it up so you have half a gallon (64oz) of working solution.

6. Stir or shake.