Law of Thirds

As I have been researching further into how to use aperture and shutter speed in photography, the Law of Thirds, is an element which could effect a photograph when playing with depth of field. 

For landscape images if you mentally divide your space up into 3 horizontial and 3 vertical lines: these are considered as the ideal focal points in trying to take a correct photograph. 
The upper and lower lines are ideal horizon point for landscapes, the lines help position how much sky is needed in the photograph. The law of thirds supports depth of field becuase it will give the photograph a correct composition supported linear perspective. 

Alternatively, law of thirds can also apply vertically linking to linear perspective; it can alter the composition of the photograph through weighting of the landscape. The photograph below supports this as I have used the law of thirds grid to apply a sense of shape and structure to the image.