Search results
Results from the WOW.Com Content Network
The postage stamp appears larger with the use of a magnifying glass. Stepwise magnification by 6% per frame into a 39-megapixel image. In the final frame, at about 170x, an image of a bystander is seen reflected in the man's cornea. Magnification is the process of enlarging the apparent size, not physical size, of
where N is the uncorrected f-number, NA i is the image-space numerical aperture of the lens, | | is the absolute value of the lens's magnification for an object a particular distance away, and P is the pupil magnification. Since the pupil magnification is seldom known it is often assumed to be 1, which is the correct value for all symmetric lenses.
In astrophysics, L is used for luminosity (energy per unit time, equivalent to power) and F is used for energy flux (energy per unit time per unit area, equivalent to intensity in terms of area, not solid angle). They are not new quantities, simply different names.
Note that when this definition is used, the connection between the numerical aperture and the acceptance angle of the fiber becomes only an approximation. In particular, "NA" defined this way is not relevant for single-mode fiber. [7] [8] One cannot define an acceptance angle for single-mode fiber based on the indices of refraction alone.
The pupil magnification of an optical system is the ratio of the diameter of the exit pupil to the diameter of the entrance pupil. The pupil magnification is used in calculations of the effective f-number , which affects a number of important elements related to optics, such as exposure , diffraction , and depth of field .
Moving the object nearer to the lens amplifies this effect, increasing magnification. [10] The highest magnifying power is obtained by putting the lens very close to one eye, and moving the eye and the lens together to obtain the best focus. The object will then typically also be close to the lens.
The cardinal points of a thick lens in air. F, F ′ front and rear focal points; P, P ′ front and rear principal points; V, V ′ front and rear surface vertices. The cardinal points lie on the optical axis of an optical system. Each point is defined by the effect the optical system has on rays that pass through that point, in the paraxial ...
Snell's law (also known as the Snell–Descartes law, the ibn-Sahl law, [1] and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or