15 acres is a little bit to see all the way through the corn so if the field is surrounded by woods on at least 3 sides I would get you a good lane as far across as you can shoot... I would make it 4-6 yards wide... Deer like edges and then tend to travel along edges and if you gave that much of an opening you could shoot them crossing and traveling down that path... I think that is going to be your best bet... but that is just my 2 cents...