Shorter wide angle lenses

When wide angle lenses are shorter than 28mm, their covering power and other characteristics change rapidly. Lenses in the 21mm to 28mm range lie halfway between the moderates and the super wide. They have greater angles of view and depth of field than the moderates, but they still avoid the distorted, unreal perspective sometimes associated with extreme wide angles lenses.

Lenses this short are more difficult to correct for aberrations, so maximum apertures are smaller than those of normal focal length lenses, or even of moderate wide angles. The reduced light gathering power often leads to focusing problems, especially in dim light. These lenses have great depth of field to begin with, and a smaller maximum aperture only increases it further. Add to this the fact that less light reaches the viewfinder, and you can understand why it is sometimes impossible to tell just where exact focus is. Not always knowing the point of focus is not a serious drawback, however, for the extensive depth of field covers all minor focusing discrepancies.

A lens of any focal length will”distort” a flat surface (such as the wall of a room or the front of a building) if the camera isn’t held perfectly level. You would have seen a building falling over backward when a camera has been pointed up to take in the top or the picture of a room in which the floor looks smaller than the ceiling because the camera has been pointed downward and the walls seem to converge toward the bottom. Any lens will produce these results to some degree if the camera isn’t level, but the shorter the focal length and the wider the angle, the greater the apparent distortion. Wide angle lenses in the 21mm to 28mm range are especially vulnerable. The remedy is to keep the camera level unless you are trying for bizarre effects. A tripod often helps.

Mid range wide angle lenses are invaluable for really tight quarters indoors or out. When the camera is held level, the generous angle of view takes in surprisingly large subject areas with great depth of field and no apparent distortion.


More about telephotos lenses

- Moderate wide angle lenses
- super wide angle lenses
- tips about using wide angle lenses
- fisheye lenses
- tips about using fisheye lenses