“One of the most appealing attributes of landscape photographs is sharpness from front to back. Everything is in sharp focus in the foreground, middle, and background, allowing the viewer to be pulled into the image as if they were standing right there.” – Max Foster
Generally speaking, sharpness throughout the image, that is from foreground to background, is far easier to achieve with an ultra-wide-angle lens (UWA) than with a tele. However, even wide-angle lenses have their limitations. If you place a UWA lens only a few centimeters from the foreground object, you can get it in focus. The background, however, will fall outside the depth of field and be blurred. The same goes if you focus on a very far object.