Depth of field is the distance between the closest and farthest objects in a photo that appears acceptably sharp. Unfortunately, a camera can only focus sharply at one point. However, the transition from sharp to unsharp is gradual, and the term ‘acceptably sharp’ is loose! Without getting too technical, the device you view footage on and the size of the screen contributes to how acceptably sharp the picture is. However, it also depends on how good your vision is.