Quote Originally Posted by Alan Johnson View Post
In an unplanned experiment I left a bottle of D-316 on top of a hot water tank for about 2 weeks. The D-316 temperature varied between ~35~50 C, say 40C average.Upon noticing it was there I opened it,still hot, whereupon it foamed and bubbles came out of the solution.2 days after it had cooled to room temperature I noticed that it had formed tiny suspended crystals in half the bottle, see pic.
Your picture is identical to the crystallization that I've often seen: The solution collapses, producing a separated liquid and cream. I've known that D-316 is close to the edge of the crystallization-cliff, because I've seen white smudges of the start of crystallization on the bottom of a beaker when mixing it hot (85C). Your test evidently pushed it over the cliff. Congratulations. Actually, this is good news because it gives us a way of stressing a concentrate, and the same test can be done with the final developer. I suspect that the ratio of sodium metaborate to ascorbic acid largely determines vulnerability to crystallization, and the latest developer, 214D, has a lower ratio, so it's hopefully more robust.

Yesterday, I shot and developed an important roll using Delta 400 and 214D. Results are beautiful. Here's an example taken in mediocre indoor lighting at box-speed:


Mark Overton