If you want higher acutance with Tri-x (or HP5+, Delta 400, TMY or Fuji Neopan 400, all of which are sharper and finer grained than Tri- x) use PMK or Pyrocat-HD. You'll get less prominent grain, much better acutance and more pleasing tonality.(posted 8059 days ago)Of course these developers are not designed for divided use. I don't think I'd try this with PMK, but you probably could figure out a way to get good results dividing Pyrocat-HD. Since it's already divided, you could try mixing A and B parts separately at 2X strength, using each bath for 3-5 minutes. That should put you in the ballpark.