when i am in town and i go upp. all is ok but when i go down the camera will not zoom down its far away is it a bug???

From my experience the camera does have problems depending on the terrain. Double clicking on one of your characters portraits fix it, by focusing the camera properly on that character.

If the camera is not locked onto the lead character, it does not automatically readjust height (by design). In addition to double clicking the leader's portrait to do so, you can also hit Home (on PC), cycle between characters ( [ or ] keys), hit one of the character selection keys twice (F1-F4) or click and hold to move your characters briefly. Saving or starting a conversation will also recentre the camera and reset the height.