K. Portra. F. Astia. Any 'regular' BW emulsion (and the 'irregular' K. Technical Pan); normal or C41 process. K. Verichrome (still avail.?). K. Ektachrome (lotsa flavours to choose from...).(posted 8811 days ago)Grab a couple of rolls of each, and then make a personal decision. Most of the time, for negative film I'd reccommend you knock about 1/3 of a stop from the Rated ISO, but don't say anything to your lab (i.e., have them develop it normally). If you have the time, develop your normal-process BW films yourself.