hi. thanks for your comments and question. the negs from 3 rolls of tri-x 400 came back blue for some reason, so all the scans seem to be about one full stop underexposed. i'm assuming this is due to the heavy blue/purplish tint of the negs, as other rolls of the same film that i've developed at home are clear, not blue/purple, and have scanned fine. post-processing comprised lifting the middle tones by about a third of a stop and increasing exposure by a little less than a third.