What is the lens?
The word "objective" is derived from the word "object". An objective is a part of an optical system, which in turn is part of an optical device. Let's try to understand what a lens is like an optical system, and in what devices it can be present.
The lens is a lens system in one frame,by means of which an image (imaginary or actual) of an object of observation or shooting is formed. Lenses are present in the following optical instruments:
- Devices intended for the formation and imprinting of the image of the object: cameras, film and video cameras.
- Observation instruments: microscope, telescope, binoculars.
- Measuring optical instruments: rangefinder, optometer, etc.
Lenses differ in design, in the form of optical correction, in focal length. These and some other parameters constitute the main characteristics of the lens. Namely:
- focal length;
- light intensity;
- angle of view;
- resolution (resolution);
- character and level of aberrations (optical distortions);
- the multiplicity of the zoom (the ability to approximate the observed object).
With the development of photography, film and television, the word"Lens" has become widely used in the media. There appeared and fixed such a stable expression as "to get into the lens" - to be imprinted on a photo or film. For example: "Unsuccessful office robbers got into the camera lens".
Read also our article How to remove the lens.
