D316 is a two-part developer consisting of sodium sulfite powder and a liquid concentrate. I'm finding that it's convenient to measure both by weight. Electronic scales are cheap. Search on amazon for "scale .01g". They typically cost about $15, and work well in my experience. That's the cost of just three rolls of film. At that cost, there's no excuse for a darkroom to not have one. To mix this dev:

1. Put a plastic beaker on the scale and press Tare to zero it.
2. Pour in the correct weight of liquid.
3. Press Tare to re-zero the scale.
4. Pour in the correct weight of sulfite.
5. Add water to fill-line and stir for 3.5 minutes to dissolve.

D316 weighs 22.8 grams/litre. And you need 45 grams/litre of sulfite. So to make 250 ml of dev, pour out 5.7 g of liquid and 11.3 g of sulfite.

I prefer to do this than deal with air in bottles of XTOL plus the initial mixing of 5L of XTOL. All things considered, D316 is not much less convenient than XTOL. It's fine for occasional shooters of 1-2 rolls/month for whom the few extra minutes of measuring and stirring won't matter.

Mark Overton