Quick Intro: Field of View vs. Focal Lengths

[TrekRover]

Each red frame represents the Field of View (what you would see) if you used the Focal Length (mm) on your camera lens from the same spot where you're standing. The smaller the focal length (ex: 24mm) the more you can see and capture in your photo. The bigger the focal length (ex: 1200mm) the less you can see as you zoom in and magnify the object.