Objective is a term that generally indicates an optical device capable of collecting and reproducing an image. The optics of the camera has the function of projecting the image of the scene that we want to photograph on the focal plane where the film or the sensor is located. To classify lenses, it is essential to know the angle of view.
The field angle is the visual angle that a certain lens can capture. This is determined by the focal length and size of the sensor or film.
The focal length indicates the distance between the optical center of the lens, and the plane of focus, usually measured in millimeters.
Goals can be categorized into three main categories: normal / standard, wide-angle and telephoto lenses .
- The normal optics has a field angle similar to that of the human eye, around 45 ° and a focal length of 50mm. They can be used a bit for everything, but give the maximum for portraits. ( https://www.white.film/prodotto/ottica-canon-50mm/ ) li>
- The wide-angle lens has a larger angle of view than the normal lens. Its focal length is always smaller than the normal lens. They are suitable for architectural photos but also for landscapes. In this large category there are various types of optics, from 35 to 6mm, including fish-eye (https://www.white.film/prodotto/samyang-8mm/) that cover a visual angle of 180 °.
- The telephoto lens strong> has a focal length greater than the standard optics and the field angle is smaller than the human eye. They are ideal for nature photography but also for portraits and photos in urban settings. ( https://www.white.film/prodotto/canon-70-200-f2- 8 / )