Enable the Debug Mode Camera in Dungeons
When you're in a normal map - i.e. a Georama - use R2 to go into first-person mode, then go to any dungeon floor by entering the menu and using Move. In the dungeon, immediately go to the menu and equip the fishing rod and exit the menu. Just like that you have glitched the camera to be much like the debug mode camera, in that you can go at any angle desired; pausing and unpausing will change the camera distance. Unequipping the rod will rectify this state.