Understanding the inner workings of a camera and its lenses is often complex and confusing, but this knowledge helps to create freedom of creativity. Once a photographer understands exactly how photography works he or she can then manipulate it to create the shot exactly as they want it. Choosing the wrong lens for a shot can result in chromatic aberration, blurring, loss of contrast, distortion and vignetting. Choosing the correct lens to minimize aberrations is the ideal here. Aberrations are imperfections in the image and can refer to colour, blurring, contrast and a range of other flaws in the photo.
When choosing the focal length, remember that the angle of view is dependent on it. Wide-angle lenses have short focal lengths, whereas telephoto lenses with a narrow angle have longer focal lengths. In some shots wide-angle lenses can also cause exaggerated perspectives, but this depends on the particular type of shot. In general for sports and wildlife photography and portraiture a telephoto lens or medium telephoto is most suitable. For landscape and architecture a wide-angle lens and extreme wide-angle is best. For street and documentary work a normal camera will provide the best results.
Regarding exposure times, shorter times are needed for longer focal lengths and vibrations are magnified with distance so it is important to bear this in mind depending on the type of shot. The benefit of zoom lenses is that they are much more adaptable with dynamic subjects such as children and it is easier to vary perspectives without lens changes. With prime lenses they are often cheaper without having to compromise on quality. They are also a great deal lighter and quicker. In the past they used to be significantly better quality optically, but now the difference is not easily noticeable. The correct lens is essential to a high quality photo and a high number of pixels are often not as important as a high quality lens.