Get Your Horizon Line Straight, Method 2

If you bought your camera in the last couple years or so, there’s a better-than-good chance you have some kind of digital camera level built right in. They tend to look a lot like the aviation-style artificial horizons pilots use to keep their wings straight while flying—so the passengers in back aren’t screaming in panic the entire flight as their drinks slide off their tray tables. That’s probably more information than you needed, but anyway, in many cases, they’re built in (check the PDF of your camera manual to see if you have one), because having a straight horizon line matters.