Slowing down the development process without diluting or lowering temperature?

[l2oBiN]

I am currently developing with Xtol 1:1/20degC/5min rotary(3010). I am using time as my negative development determinant. I would like to extend the development time without changing the temperature, rotation, or dilution so that I can more precisely fine-tune different effects by altering development time. Is this possible?

[Jay DeFehr]

Yes, it's possible, but it's not entirely without compromise. You could add a restrainer to your developer, for instance, but it might have an adverse effect on your film speed.

What kind of effects are you wanting to fine-tune?

[Ed Richards]

What film?

[l2oBiN]

I am tuning Foma 100. The 5minute mark is good, but I would like it a bit less dense.. perhaps 4min or so (but I have tried this time yet). However, I feel this might be a little too imprecise to achieve consistently.. so for example, I would like to have the 4minute marke equivalent to 8minutes developing.

I am developing for a scanning workflow..

[Gem Singer]

Reduce the frequency and amount of agitation.

[l2oBiN]

Gem, the 3010 is on a continuous agitation base.. I dont think I could just stop it.

[Jay DeFehr]

I think the first thing you should do is test your assumptions. Find the development time that gives you the results you want, and then test it for consistency. There's no point in trying to solve a problem you only suspect exists. Scanning is very tolerant of minor variations in film contrast.

[Leigh]

Do test developments at 4 1/2, 5, and 5 1/2 minutes, and compare the results.

You can easily control your times within a couple of seconds.

- Leigh

[Ed Richards]

Xtol preserves film speed, and may even increase it. 5 minutes at 20 is really short for Xtol 1:1. (I think FOMA's recommendation of 5-6 minutes is for undiluted Xtol.) My bet is that you are significantly over exposing your film. Xtol 1:3 works very well and will extend your developing time by about 30%. If you exposure is correct, then I would go to 1:3 to get better working times. But I would start with a proper film test. (Or just be lazy and and shoot a sheet at 1/2 and one at 1/4 your normal exposure and see if the shadows are still OK.)

[venchka]

I can't speak for Foma 100 yet. I'll get some soon.
In the meantime: Foma 200, exposed at 100, developed in Xtol 1:3, Jobo 3010, Beseler base @ 30-32 RPM, 75F @ 7:45. Works for me.
I expect the Foma 100 shot at 50 and the time tweaked a bit would also work well.
5 minutes is way too short when working with a Jobo 3010, motor base and funnel with tube. I was nervous about using 7 3/4 minutes in the summer. I am much more comfortable with 10 minutes @ 68F. That only happens in Houston in the winter.
Good luck.

[IanG]

There's no easy way of slowing down development, a restrainer will alter the films speed and contrast. You've ruled out dilution which is the ideal method, you could use 1+2.

It's possible that adding a sugar to the Xtol may be enough to slow down development. Typically you'd need to start with approx 20g/litre of Glucose (Dextrose). This was a method used in some super fine grain developers, essentially the sugar gets in the way reducing the speed of development.

Another alternative is add a small amount of Sodium or Potassium Metabisulphite (must be the Metabisulphite not Bisulphite) to lower the pH which will mean much longer development times. Too much will cut the film speed, D25 is D23 with 15g/litre Metabisulphite that cuts film speed in half along with a doubling of dev time. I'd suggest somewhere between 1-5g (start with 2g) may be enough to extend the dev time to a more manageable level.

Ian