In an optical system, the entrance pupil is the optical image of the physical aperture stop, as 'seen' through the optical elements in front of the stop. The corresponding image of the aperture stop as seen through the optical elements behind it is called the exit pupil.

The entrance pupil (EP) is the image of the stop into object space, and the exit pupil (XP) is the image of the stop into image space. The pupils define the cones of light entering and exiting the optical system from any object point. There is a stop or pupil in each optical space.

The entrance pupil is the apparent aperture as seen from the object side. One solves that problem by constructing the so-called entrance pupil, which has a certain diameter and axial position. In Figure 2, this is shown for the system as above, but containing only …

The entrance pupil is defined as the image of the aperture stop as seen from an axial point on the object through those elements of the lens which precede the stop. The exit pupil is the image of the aperture stop as seen from an axial point in the image plane.

Entrance pupil: Image of the aperture stop as seen from the object side. Defines the cone of light accepted by the optic. The importance of the entrance pupil is that the brightness of the image depends on this cone angle. The larger the acceptance angle, the more light that is collected from each object point, and hence the brighter the image.

2022年10月15日 · \$\begingroup\$ The entrance pupil is measured from a point on the center of the lens' optical axis. The entrance pupil can be larger than the lens' objective diameter in the same way that one can look through a keyhole and see more of the room on the other side than an area the size of the keyhole.

2022年9月16日 · The entrance pupil is the image of the aperture stop by all elements to the left of the aperture stop. If there are no lenses between object and aperture stop, the aperture stop itself is the entrance pupil.

The entrance pupil is the image of the aperture stop when it is imaged through the preceding lens elements into object space. The exit pupil is the image of the aperture stop when it is imaged through the following lens elements into image space.

The virtual image of the aperture for lens I (as seen from the object point) is called the entrance pupil. The amount of light leaving the object and traversing the system is limited, in effect, by the entrance pupil, just as it is actually by the stop aperture.

The meaning of ENTRANCE PUPIL is the stop in an optical instrument or the virtual image of the stop that determines the angular diameter of the bundle of rays traversing the instrument from a given point in the object space.