The classification of the lens

Date：2012-12-22

1. According to the sort of lens classification (according to application occasion classification)

 Wide-angle lens: Angle of 90 degrees above,  observation range is larger, close shot will be deformation.

Standard lens: Angle of 30 degrees or so, with wider range of use.  

Telephoto lenses:Less than 20 degrees Angle, focal length can reach dozens of millimeters or hundreds of mm.   

Zoom lens: The lens focal length continuous variable, the focal length can be from wide Angle to telephoto, the longer the focal length is the bigger the imaging.  

Pinhole lens: Used for covert observation, are often installed in places such as ceiling or wall.  

 2. According to the size of the object, the relationship between distance and focal length classification

1) Fixed focal length: fixed focal length, can be divided into having aperture and no aperture

Have aperture: the size of the lens aperture can be adjusted. According to the variation of environmental light, should be appropriate to adjust the size of the aperture. The size of the aperture can be adjusted by manual or automatic. Artificial manual adjusting aperture are called aperture manually. Automatically adjust aperture lens with micro motor are called automatic aperture.  

No aperture: set the aperture, the light is fixed. Mainly used for constant light source or camera built-in electronic shutter.

2) zoom: the focal length can be adjusted according to need, to be enlarged or reduced image of the object.

1' Commonly used zoom lens for six times, ten times zoom, etc.  

2' Three variable and two variable lens:

Three variable lens: Adjustable focal length, Adjustable focus, adjustable aperture.

Two variable lens: adjustable focal length, Adjustable focus, automatic aperture.