If you chose a wide aperture setting (f2.8 or f/4) and again keep your subject closer to the lens you can achieve a similar effect of blurring in the background that a long lens brings.Moe Doiron/The Globe and Mail
PLEASE NOTE: Most digital SLR cameras have what is known as a cropped sensor. What this means is the size of the digital sensor's coverage area is smaller than that of a full size 35mm frame. As a result there is a slight magnification to the lens that you're using. In most cases it is a factor of 1.5x. So a 24mm becomes a 36mm when compared to a full-frame camera. However this should not affect what you see through your viewfinder.
Wide-angle lenses are probably the most often used lenses in photography. A wide-angle is generally understood to be a lens with a focal length between 16mm to just under 50mm.
Available in many variations in both zoom and fixed focal lengths, a good wide-angle will be a valuable tool that you can apply to almost every photographic situation. Although zooms offer the photographer more flexibility over fixed lenses, they do have some shortcomings. We'll take a look at these features and hopefully help you decide what lens, or lenses, will work best for you.
There is a general misconception that a wide-angle lens is mainly used to capture "wide" views, landscapes, or vast panoramic vistas. Of course they are perfect for this but they are also excellent portrait lenses when used properly.
Inherent with wide-angle lenses, especially in the 16 to 24mm range, is distortion. Without getting too technical, the lower the 'mm' number the more lens distortion you get. Distortion can also be caused (and controlled) by the distance between you and your subject (closer to the lens, more distortion) and the angle in which you point your camera (tilt up or down also increases distortion).
That's not to say that distortion is bad. In many cases it can be used as a positive effect. For instance it can help focus attention to parts of your photo by accentuating the foreground to background in size and depth, or perspective. By placing your subject close to the lens while keeping the background at a distance you can make your subject stand out more.
Another characteristic that these lenses have is a very wide range of depth-of-field. For instance it's common to use such a lens when trying to keep both foreground and background in sharp focus. Keep in mind that the aperture setting you use will also influence how much depth of field you can achieve. An f/16 setting provides dramatically more depth-of-field than f/4.
But each pro comes with a con. What if the photo that you're trying to compose doesn't call for having everything in focus? Switch to a telephoto?
Not necessarily. If you choose a wide aperture setting (f2.8 or f/4) and again keep your subject closer to the lens you can achieve a similar effect of blurring in the background that a long lens brings.
It's best to experiment with various settings and you'll soon start to get a feel for how the lens will react.