In 2008 Canon starting adding a video mode to their DSLR cameras. They had no idea the phenomenon that it would bring. DSLRs have huge sensors (the mechanism that converts light to video) and way more, cheaper, high quality lenses (also referred to as “glass”). These factors give DSLR cameras very sharp imagery as well as a very shallow depth of field. Depth of field or Dof, refers to the focus of the image or video. A deep Dof is when the foreground and the background of an image are both in focus. You see this commonly in landscape shots.