How to Level Your Canon EOS 6D
The Canon’s electronic level enables you to take pictures with your camera level and plumb. This ensures that the camera isn't tilted right or left, or up or down. The end result is you get images that look correct and not like they were photographed by a drunken sailor.
When you’re not shooting in Live View mode, the electronic level is most useful when you have the camera mounted on a tripod. To display the electronic level on your LCD monitor:
Mount your camera on a tripod.
You can also use the electronic level when handholding the camera. However, it’s more difficult to get accurate results, and you can’t hold the camera as steady because it’s away from your body.
Press the Info button twice (yes, this means two times).
The electronic level displays on your LCD monitor. The left image shows what the level looks like when the camera isn't level horizontally and not plumb.
Adjust the legs of your tripod until a solid green line appears in the center of the level.
This tells you the camera is level and plumb. No crazy tilted pictures unless you want them that way.