Effect of developer dilution

[Brian Sims]

I'm switching to Xtol (from TMAX-RS). I've one last decision to make: full strength or 1:1. I'm trying to understand the effect(s) of the dilution of developers. Let's say the reason you are diluting a developer is NOT to get a long enough development time to solve agitation problems. And the reason isn't simply to conserve developer. Can someone explain how a diluted developer affects image quality compared to stock solution (all other variables remaining constant except for time)? Thanks.

[C. D. Keth]

I ahve heard that sometimes dilution can affect contrast in subtle ways, but I don't know if it's all developers or which way contrast is affected.

[Ron Marshall]

This is from The film Developing Cookbook, by Anchell and Troop:

"At a moderate dilution of 1:1 sharpness is increased while effective film speed is maintained. Graininess is slightly increased on dilution ... but the increase is small ..."

They also say that a high subject brightness range is handled better when a solvent developer is diluted.

I use XTOL at 1:1 or 1:2.

[Ed Richards]

I use Xtol 1:3 in Jobo Expert drum. I get a very good tonal range, and the grain is very fine, as long as the film is not over exposed. Since I am usually using 75 degree water, 1:3 is also necessary to keep the developing times reasonable.

[Bruce Watson]

I use Xtol 1:3 in Jobo Expert drum. I get a very good tonal range, and the grain is very fine, as long as the film is not over exposed. Since I am usually using 75 degree water, 1:3 is also necessary to keep the developing times reasonable.

Like Ed, I'm using XTOL 1:3 in a Jobo 3010 drum. I'm doing it at 20C however.

What happens when you increase dilution, in part, is that you dilute the solvent. This tends to makes the grain a little bigger with a small gain in apparent sharpness.

The effect is quite subtle however. I doubt that you'll see it at all with enlargements less than about 12x. I actually talked to Silvia Zawadzki and Dick Dickerson (XTOL's "parents") about this and they said I wouldn't really begin to see the difference until 15x. And for a 5x4 negative, that's a 75 x 60 inch print. I don't know how to make a print that big, so it's really a moot point, eh?

So... Like Ed, I do it for the extra control. The economy is a plus, as is the slight gain in real film speed.

[Michael Heald]

Hello! Plus there is a minimum amount of developer required per area of film, regardless of how that developer is diluted. Best regards.

Mike

[Ed Richards]

> Plus there is a minimum amount of developer required per area of film

Right, but for the 6 sheet expert drum, the minimum amount is less than the minimum the drum needs, so you do save a little by diluting it. This might be more significant in tanks that take a bigger volume. I am assuming we are talking about using it as a one shot. If you want to reuse it, then working with more concentrated solutions makes sense.