Experimental role in the neighborhood. Having ruled out water, film, fixer it was time to see if the Diafine was the cause of the dark spots. Purposefully changed the process with a (shudder) pre-soak, DIRECTLY AGAINST the recommended manufacturer instructions! Well, no black spots this time, albeit with less contrast. But, since I was using the Canon7 with f0.95 lens, taking advantage of low light to see what happened. No need to discard the Diafine. Thanks to my fellow flickerarians during this challenging time to keep the faith of image creation strong!!