Perspective is all about using visual clues to emphasise dimension. Your picture needs to use defined edges, lines and direction to give the eye something follow into the image.
• Perspective • By Netkonnexion on Flickr 
The concept of perspective is related to visual clues.
What we see in the world around us is created in our heads. We see things in the environment and from that build up a picture. Here we look at the sense of perspective.
Visual clues
Previously in ‘The easy way to give depth to landscapes’ and Easy introduction to ‘visual elements’ in photographs I introduced ‘visual elements’. These are strong signals in the world that help us see. They are mostly edges, lines, curves, shapes, form and so on. We see things because the edges of objects have a detectable contrast with something beside it. Our eyes spot that change and, in doing so, see depth. Edges give us strong clues about the nature of our world so our eyes are trained to follow them.
The nature of perspective
Our innate sense of perspective has always been there to enable us to function as biological animals. Perspective in art is a different matter. In terms of human history reproducing perspective has been a late arrival (see: Perspective – compositional ideas). What made the difference was understanding the relationship between lines, or in natural terms, edges.
Three dimensional geometry explained the way lines created depth. This geometric depth also mimicked form in nature. On mastering the idea of a cube or other geometric forms we see how the lines work. If you look at a cube corner you see three edges trending away from you. You are looking at depth created by the edges.
Parallel lines provide strong perspectives. In the picture above there are lots of parallel lines which give depth to the picture. The main red line – the bus lane – is a vanishing point perspective or ‘single point’ perspective. It is notable by its coming together (convergence of the lines) near the horizon. By experience we know this is a long distance away. The convergence has created distance into the picture.
In the bridge there is ‘two point’ perspective. You can see depth because the darker underside is defined by its lighter up-edge (the wall of the bridge). This two-point perspective exists for us even though we cannot see the roof or the other side to confirm ‘form’ (3D) rather than shape (2D).
Of course the glass stairway to the bridge has three point perspective. Like the cube we can see depth – the top edge of the building, the bottom edge of the building both converge (two point). The convergence imparts depth. However, the width of the building (shown by the top and bottom edges), and the height gives us the three dimensions. Our visual clue for this. on the front-face. is the non-convergence of lines in the width/height plane. Although this front-face is a curved glass wall we can still see it does not have a distance perspective away from us.
All the clues are there
You now have the clues, or visual elements to determine depth through perspective. Converging lines with distance from the eye impart a feeling of distance away from you. Parallel lines with no convergence give you flatness or non-distancing when they face you. This works with both height and width.
I chose the picture above for the strong perspectives that it imparts. The powerful lines make it easy to see the almost exaggerated proportions that contribute to perspectives. Sometimes its not so easy in nature. Have a look at the picture below…
Looking up the River Thames from Marlow, Bucks, UK. The perspectives are not as clear as direct straight lines. Yet the picture has depth because we are adept at seeing ‘edges’ and trends in lines when we look at nature.
Click image to view large.
• Looking up the River Thames • By Netkonnexion on Flickr
The edge on the right hand side looking up river barely exists – it disappears off the side of the shot. Yet the small part that is there at the top
implies there is a bank all the way down the right. The left bank on the other hand is not well defined as a line. However, our eyes are trained to see it as a ‘trending’ line. The line of trees (left) and the implied line (right) therefore creates a converging pair of lines in the distance to where the river rounds the bend.
Despite there being no strong lines in this picture we can see a converging point perspective. Dimensionality is added by the height of the trees and the width of the river. The width diminishes between the two banks as we look progressively up stream, more evidence of distance and convergence. The height and width we intuitively know because our eye determines sizes by measuring them against boat and people sizes (known element sizes). Perspective is all in the visual elements.
Understanding is not precise
We do not all understand perspective in the same way. Some notable art schools have denied our innate understanding of perspective and space. The Cubists are an example of this, notable among them Pablo Picasso the famous Cubist painter. Nevertheless, we all understand depth in the world around us. We don’t live in a two dimensional world. However, in our images we have to create the sense of depth in a two dimensional medium.
The second picture, the river scene, shows us how to define depth. We need, as photographers, to become observers of lines and trending lines. Similarly, we should be able to spot shapes and forms that are both defined and ill-defined. Then we need to be able to view them as if a geometric model. If we can see these lines, in nature and in man-made things, then we can find ways to compose our picture to bring them out. It is this last part that is the most important part of the composition process.
If we give the viewer a perspective in our shots, we create a world. We want it to be a three dimensional world that the viewer can imagine going into. When we choose compositions that emphasise these lines we dispose of the two dimensional picture and create an image to look into.
By Damon Guy (author and Photokonnexion editor)
Damon Guy (Netkonnexion)
Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photographers.
See also:
Editors ‘Bio’.
