Well, I took the plunge and signed up for a 4x5 class at my local community college - wonderful place with great facilities and equipment. Even lent us all nice Cambo 4x5s with tripod and case. Here's my problem - all of my films are coming out thin by at least 1 to 1.5 stops. I have been shooting Delta 100 (@100) and HP5+ (@400). I am very anal about exposure (with grey card), focus, bellows draw and reciprocity failure. Shooting mostly at f64 because our instructor insists on "razor sharp" fore to back. I am tray developing in HC-110B at 20C. The Delta 100 gets 6mins and the HP5+ gets 5 mins. I can process 4 to 6 similarly exposed sheets without scratches and I'm using a 2 min presoak before development. i plan to underexpose both by a stop and see whats up but just underexposing to compennsate without some real reason really bothers me. help!