It has been awhile since I used this spell, but after you right click to activate Wizards Sight, you should just need to left click somewhere covered by fog-of-war to have it temporarily cleared (or, IIRC, see through building roofs). Cast it a second time in the same spot, before the first wears off, and the fog-of-war will be permanently cleared (useful for clearing black areas of the map you can not otherwise reach). You can hold the shift key down to move the screen focus away from your character, and further into unexplored territory.

BTW, if you edit your duplicate post in the BD forum, there is a 'delete this post' button beside the 'change this post' button, which will also remove the topic, as long as nobody else replies.