Go to Electro sniper hill (Dobry), have any sniper rifle with hunting scope on you (assign to hotkey 1) and a range finder with 9v battery (assign hotkey 2). Take out sniper rifle, lay down, go in scope view, pick some target in the valley (zombie, building, bush.... not important). Now hit "2" to swith to range finder to measure the distance. Range finder view will appear all the way down so you'll have to drag it all the way up like it used to be with a hunting scope before ads bug fix.