70-200 how far can the lens be taken

Generally speaking, telescope = standard mirror N times, that is, telescope lens/standard lens = multiple, also means, for example: a 200mm long telescope lens, shooting 200M scenes, the image obtained, if the standard lens is taken with the same size, the same size is taken with the same size. Image, (theoretically) must be taken at 50M from the scene! (Such push)

Lens profile

The lens has two fingers in the film and television. One fingers of a movie camera and a screener to generate an optical component for generating images are composed of multiple lenses. Various different lenses have different styling characteristics. Their application of their photography styling constitutes a means of optical expression; a continuous picture taken from booting to shutdown, or fragments between the two editing points , Also called a lens. One finger and two fingers are two completely different concepts. In order to distinguish between the differences between the two, the one is often referred to as the optical lens, and the two refers to the lens screen.

According to the origin of the lens, the classification of the lens is mainly Japanese lens and German lens. Japanese lenses are mainly color reducing, moral mirrors.

The layering of the head is relatively strong. The Chinese shots in the market have gradually occupied a certain market, mainly because the price is relatively low.