Most of us understand Depth of Field and use it to our advantage to do things like blur the background in portrait and close-up photos. But you can also use it, as demonstrated above, to keep the entire scene in focus. The basic concept behind this is called Hyperfocal Distance and is fairly easy to understand. If the lens is focused at it's hyperfocal distance everything from a point half that distance to infinity will be in focus. This is the way most digital cameras work when set to the landscape setting. If you are using a superfocus or DSLR with manual focus, knowing how this works can help you get the shot you want.
To demonstrate this look at the scale on this lens. This lens is focused at 5 feet which gives it a DoF of 2.5 feet (1/2 the Hyperfocal ) to infinity. If you don't have a lens with these markings but have a smart phone there are DoF apps for both Android and iPhone which will do the calculations for you.
Are you ready to go out and give this a try?