The bubble on the head tells you the head itself (and camera) are level, but if you need to pan the head the base should be level, not merely the camera. The leveling base makes it easier than trying to adjust tripod legs to achieve level.
The bubble on the head tells you the head itself (and camera) are, but if you need to pan the head the base should be level, not merely the camera. The leveling base makes it easier than trying to adjust tripod legs to achieve level.