This exercise considers the impact of focal length and viewpoint. The brief was to first select a long focal length and compose a portrait shot then walk towards the subject and take a further shot at a short focal length. By doing this, two variables have changed, the focal length and the point of view and the difference this makes to the perspective distortion can be easily seen.
I chose my 55-210mm lens (cropped sensor) at its longest and shortest focal lengths.
The first image here is at 210mm and I am standing at a considerable distance from my subject. I chose F8, 1/320 and ISO 250. I didn’t want a wider aperture because I wanted a recognisable background but couldn’t go narrower because I did not want to slow the shutter further.
The second image is at 55mm. I am positioned much nearer to my subject. I stayed with F8 and ISO 250 but the shutter is now 1/500
Notwithstanding the obvious clues here, these images could have been taken at different locations. In practice, my model did not move. However, the backgrounds are very different. In the first image, the objects in the background are brought very much closer by the effect of the long lens, which has flattened the perspective. The second image has much greater sense of depth, more objects have appeared in the scene and more sky is visible.
Stephen Shore, in his book The Nature of Photographs says:
Any change in the vantage point results in a change in the relationships (of objects in the image) (Shore 2010: 42)
Anyone who has closed one eye, held a finger in front of his or her face, and then switched eyes knows that even this two-inch change in vantage point can produce a dramatic difference in visual relationships (Shore 2010:42)
..take one step and something hidden comes into view; take another and an object in the front now presses up against one in the distance’ (Shore 2010 p48)
I was interested to try this exercise again using a full body shot. Here are my images:
210mm, F10, 1/250 ISO 250 55mm, F10, 1/320, ISO 250
The differences here are even more dramatic since changes in the foreground are now more apparent. The lengthening of the path in the second image increases the sense of depth. The background now reveals many more vehicles, making the paddock look deeper, and look at the change in position of the yellow flag. The yellow tent, not in the picture at all in the first photograph, is in the distance in the second.
I found this exercise very interesting. The choices made by the photographer in terms of lens and vantage point have a significant impact on the final image. If the yellow flag had been the end of race chequered flag, and my image one of the rider winning the race, his position in relation to the flag would have been even more significant.
Shore, S, (2010). The Nature of Photographs: A Primer. London: Phaidon Press