This exercise is about dividing the frame by using the horizon line and how the positioning of the horizon within the frame affects the feel of the image. I have used a view of Hampton Court Palace, taken from the end of The Long Water to complete this exercise.
Positioning of the horizon can have a profound effect on the feel of an image and these photographs are just one particular example. In these images there is very little foreground detail to come into play. If, for example, there had there been a boat in the foreground, the image would have differed much more from positioning the horizon higher in the frame, as the boat would have become much more apparent in the composition. In this example, I deliberately darkened the sky to highlight how the removal of it (by raising the horizon) affected the feel of the image.
My own personal favourites are the ones with the horizon set low, simply because the sky is quite dramatic and needs to be incorporated.