At this year's Game Developers Conference, Mushroom 11 developer Itay Keren offered a fascinating, in-depth look at the way cameras have been implemented both in classic side-scrolling video games and their modern counterparts. Keren's study of the 2D camera touches on some of the medium's earliest scrolling games, like Rally X and Jump Bug, and explains the difference in approach between Super Mario Bros. and Super Mario World.
From there, Keren looks at how games like Shinobi, Rastan and Fez had their own approach to solving 2D camera problems, and goes on to look at how fighting games, the original Street Fighter and Super Smash Bros., also deal with their own issues.
Fortunately, if you didn't attend "Scroll Back: The Theory and Practice of Cameras in Side-Scrollers" at GDC 2015's Indie Summit, you can now watch Keren's talk on YouTube. You might just learn a thing or two about the complexity of something that looks so simple.