Paul Thrussell
Agent
When grain, in a transfer from a B&W print, looks very heavy only in dark places, shadows, it's usually a signal they tried to bring details from very dark areas from the print, while transfering. This recover some details, but it also brings the largest grain particles or grain agglomarations.
Similar to what happens when you try to scan still negs/slides that weren't exposed properly. The areas where you've tried to recover detail out of overly dark/light spots are very noisy and the gradation is poor.