Friday, 14 May 2010

Exercise: Focal lengths and different viewpoints

Exercise: Focal lengths and different viewpoints - for cameras with variable focal lengths (with a zoom or interchangeable lenses)

Find a scene that has enough space in front of it to allow you a choice of viewpoint, from near to far. Avoid a flat subject; it must have some depth - a building will do, or a person in a setting. Start with the telephoto lens and make a tightly framed composition – that is, with the subject filling the frame. Study the view through the viewfinder very carefully, and remember the limits at the edges of the frame. Take your shot. Change lenses to the wide-angle. Then, in a straight line, walk forward, looking through the viewfinder until the same subject fills the frame. Take the second shot.

Figure 1 - 144mm

This first image of the sundial on the Front Lawn of our garden was taken with the lens set to 144mm

Figure 2 - 18mm

For the second image I set the lens to its widest setting and moved closer to the sundial until the subject was framed as close as possible to the original image, shown in Figure 1 above.
A couple of observations of differences between the two images can be seen, the first is around the distortion of the subject in the second image, with the base of the sundial appearing to slope towards the bottom of the base, while in the original image, the subject is seen with the base have almost vertical lines.
Also, in the first image, the subject is somewhat isolated from the background, with the background out of focus. The second image shows the background much sharper, even though the image was taken with a wider aperture, f3.5 for Figure 2, compared with f5.6 for Figure 1.
This isolation from the background gives the image a much softer feel than the overall sharper background in the second image

No comments:

Post a Comment