Why does each SLR camera have two shots?
Standard lens refers to the 50mm standard focal length of the lens, the equivalent of or similar to the human eye perspective. Take a lot of people.
Telephoto lens, commonly used to shoot distant objects or close-up, such as birds, gray chicken ... ... moon, stars.
Each focal length of the lens of their duties, complement each other.
The telephoto lens function is not possible to include all the features of the medium in the short focus lens. In about 200mm down, you can do 18-200mm, wider or longer, is still very little. More than 200mm focal length, are telephoto.
SLR cameras are not every section has two shots that are at least one lens that can be more. There is no place to spend money, with fifty sixty lens is also OK.
The lens has a certain focal lengths, it is impossible for a lens will be included in all the focal lengths.
Wide-angle lens shot and narrow interior.
Not necessarily every SLR sets of machines are double lens, there are stand-alone, but also a single lens kit.
Telephoto lenses do not mean a wide-angle or standard zoom lens function, but does not mean that they contain the focal length of the angle of view.
Different focal length of the lens, in perspective, distortion, quality, perspective, etc. are not the same, some of them can be complementary, but not entirely replaceable.
