Positioning the Camera
The position of the camera relative to the subject and background is one of the first decisions you have to make. Here are some things to consider:
- Wide-angle lenses are more prone to lens flare so the placement of lights is more critical, especially when aimed toward the camera.
- All lenses have a minimum focus distance that determines how close you can get to the subject. To get closer, you need to switch to macro mode or use a macro lens. If you get closer than allowed to any part of the setup, you won't be able to focus on that part.
- If the camera is tilted up or down, especially when using a wide-angle lens, any vertical lines on the subject will converge— an effect called "keystoning" since the lines converge like those in a keystone. There are special tilt-shift lenses for 35mm-style cameras that lets you correct for this, but they are expensive. For most of us, the solution is to use a level to make sure the camera's film plane is parallel with the vertical face of the subject.
In the left photo the camera was tilted so parallel lines seem to
converge. In the right photo the camera back was parallel to the subject so the lines appear parallel.
- If the camera is too close to the subject, the lens may block the light from covering the subject. Because of the angles involved it may cast a shadow.
- Focal length affects perspective. A subject shot from close-up with a wideangle lens will look different from the same subject shot farther away with a longer focal length.
The top photo was shot from close up with a wide-angle lens. The
bottom photograph was taken with the camera moved back and the lens zoomed in. The image taken with the wide-angle lens shows heads farther from the lens as much smaller. The image taken with a longer focal length shows the relative sizes the way they actually are.
- When zoomed out or using a wide-angle lens, it's hard to keep the edges of the setup from showing in the picture. Sometimes, there is only one angle to shoot from. Zooming in, or using a longer focal length lens from farther back, reduces this problem and gives you more flexibility when choosing a camera angle.
- Think about whether the camera should be set horizontally or vertically for the subject.
- Consider the camera angle. Do you want to shoot head-on, up, or down at the subject.
- If the camera is too close to some three-dimensional subjects, it will distort them. Any part of the subject closest to the camera will appear larger than parts farther away.
In the left photo the subject was shot from close up with a wide-angle lens. In the right photograph the camera was moved back and the lens zoomed in to keep
the subject the same size. The two images are quite different with the one on the right being much
more faithful to reality.
- If the camera is too close to a flat subject, and a wide-angle lens is used, the subject may show barrel distortion. This is most obvious in subjects with straight lines or edges that fall near the edges of the image. These lines will appear curved or swollen instead of straight. Longer focal length lenses reduce or eliminate this distortion as will using a smaller aperture since barrel distortion is less of a problem when using the center of the lens.
Both of these photos are of items with perfectly straight edges. However, both were shot from close up with a wide-angle lens and show barrel distortion with all sides seeming to bulge out.