Telephoto zoom lenses are used to photograph subjects that are very far away, making them appear closer. Many photographers use telephoto lenses for shooting wildlife and nature, because it is often difficult to get close to animals in the wild. Telephotos are also used in sports photography for shooting action from the sidelines. Telephoto lenses are practical for certain types of photography, but they have several drawbacks for standard shooting.
Weight & Size
Telephoto zoom lenses are very large, heavy and cumbersome. They are not generally considered "portable" and can be difficult to carry around and store. Heavy lenses can often result in camera shake if you are not able to brace your arm. The large size also makes it very difficult for you to shoot discreetly; people tend to notice someone shooting with a gigantic lens, which makes telephoto zoom lenses a poor choice for street shooting.
Speed
When people talk about a "fast" lens, this refers to the smallest f-stop number on the lens. The lowest f-stop number is also the largest aperture, which means it has a larger opening in the lens and allows more light to your film or digital sensor. Telephoto zoom lenses are generally manufactured with a high f-stop range and are therefore referred to as "slow." This is a drawback for two reasons: one, slow lenses do not work well in low lighting conditions and two, the limited aperture range of telephoto zoom lenses gives a shallow depth of field.
Separation From Your Subject
Unless you are specifically shooting wildlife or sports, photographing with a telephoto zoom lens separates you from your subject, which can have a result on your overall style and composition. Photographs are much more interesting when the subject is engaged or participating; shooting with a telephoto zoom lens is not interactive. When you shoot with a telephoto lens you are simply observing, not enticing a reaction from your subject to capture a moment. Some of the most dynamic street photographs are shot with wide angle and portrait lenses from a very close distance.
Price
One of the major drawbacks of telephoto zoom lenses is their hefty price tag. Buying a cheap telephoto lens will result in images that lack sharpness and clarity, but buying a quality telephoto zoom lens could run you several thousand dollars. The prince range for high quality telephoto lenses make them an impractical choice unless you shoot primarily subjects that are far away.
Tags: zoom lenses, telephoto zoom, telephoto zoom lens, with telephoto, zoom lens, f-stop number