Lead-ins are a composition technique I use a great deal. For me the purpose of a lead-in is to draw the viewer into the picture by guiding the eye. In a landscape context our eyes look to the ground so we know where it is safe to walk. Placing a lead-in in the bottom foreground of the picture plays to this fact and is a strong cue for the viewer to start to examine the image from a familiar perspective and you are led into the picture.
This structure feels familiar and allows the viewer to navigate the rest of the picture. Composition is therefore about understanding and evolving patterns that help guide the viewer through the image and engaging the viewer’s attention.
Let’s look at a picture that seems completely different:
I still think of this as a landscape picture, (I’m interested in what you think so please do leave a comment). This is a less conventional image, the only familiar reference point is the sky. There is nowhere to imagine yourself walking in this picture so I felt less constrained to have the lead-in in just one place. Now the lead-in lines dominate the picture radiating inwards from all the edges and command the attention to the crown in the middle top. Once the eye has lingered there it moves to the background and the familiarity provided by the blue sky and white clouds. The interpretation then moves from abstract pattern to some structure that is in the open air, a construction in the landscape.