Two bees in flight I photographed in Queenstown, New Zealand. If you zoom in you can see the detail of the head and the eye of the bee on the right. The one on the left is out of focus. As you focus very close to small objects the depth of field diminishes a lot: you only have an are of focus maybe 1/8 of an inch deep (or 3-4 mm ). So the focus is only on the one on the right, on the left one you can see the shape of the legs.