SLR camera lens 14mm, 16mm, 18mm, the three focal length of the viewing angle were how many degrees
You ask is not clear 'full and non-full vision is not the same' and what you ask what is the visual? Horizontal 'vertical or diagonal? Such as 14 on the full level of visual 104, the vertical is 81, the level is 114 in the non-full vision will shrink 'so you have to explain what you are on the camera
that is, the focal length of the lens has not changed. In other words, regardless of the size of the image sensor, 50mm lens focal length is always 50mm. The focal length is the distance from the main point of the lens to the focal plane of the square, and is not affected by the image sensor size. However, when the image sensor becomes smaller, the viewing angle becomes narrower, and the corresponding lens imaging characteristics tend to be distant telephoto. When using the APS-C size camera, the 50mm lens angle is equivalent to the 80mm lens, and it will notice that the focal length changes as if it were. But we have to understand, in fact, the lens itself, the structure and optical properties will not change.
Classmates, this must be multiplied by the coefficient. Multiplied by 1.5 after the focal length unchanged, but the angle will be reduced.
On 135 film 14MM is 114 ° 20MM is 94 °.
The angle of view of the lens (diagonal viewing angle) refers to the angle between the ends of the diagonal of the image focal plane (image sensor) to the lens main point (second main point) The imaging range of the subject on the square focal plane. Therefore, when the size of the image focal plane as a factor of the viewing angle changes, the viewing angle will also change. As shown in the figure, when the image sensor becomes smaller, the viewing angle also becomes smaller. Although the viewing angle has changed, the distance from the main point of the lens to the square focal plane has not changed,
