I have read the whole Altitube vs Barometric pressure thread and think i have it all figured out now. For most ballistic programs enter the station pressure and 0 for the altitude. I have read alot on this topic and I now understand it. I use a kestral 4500. So set referance at 0 on the baro screen and that is my station pressure. But from reading this thread, Eaglet wrote out a very informative description on how to enter data into exbal and in this he is saying to enter altitude as well as station pressure. I understand exbal is doing this for their sight in vs actual hunting location, but why would this now mess stuff up like it does on other programs. (By adding altitude and station pressure) Can someone explain to me why exbal does this and how they do it so the altitude doesn't affect the station pressure?