Zoom lenses can be used on any type of camera to get different view of the same image and in fact a closer picture. Hence, they are often used in cases where you are unable to get closer or prefer not to get closer to the subject, but would like a closer picture of the subject. Hence, zoom lenses are often preferred to shoot wildlife, sports etc. as it is generally the most flexible lens that allows you to shoot at different focal lengths without the need of changing the lens every time. All you have to do is, adjust the focal length as required or desired. Hence, with a zoom lenses you can only capture a closer view of the actual image you desire by eliminating the unwanted things in the picture.
Dealing with a zoom lens
The adjustment of the focal length with the zoom lens determines the distance of the image in the picture. Depending on the focal length, the width of the image changes. So, the more the focal length, the wider is the view but less close. Hence, if you want a closer view, the focal length has to be greater but remember that the width of the image will be less.
Due to this requirement, a wide variety of zoom lenses are available ranging from wide angle to telephoto focal lengths (with focal length around 70mm). So, while buying a lens, you can find the focal length on the front rim or barrel of the lens. There are about 6 different focal length lenses available. They are 10-24mm, 18-55mm, 18-105mm, 28-135mm, 18-200mm, 55-250mm and 75-330mm.
Dealing with a zoom lens is quite simple. The more you practice,you get more clarity as it all depends on the focal length and zoom of the lens.