Search results
Results from the WOW.Com Content Network
Abbe number. In optics and lens design, the Abbe number, also known as the V-number or constringence of a transparent material, is an approximate measure of the material's dispersion (change of refractive index versus wavelength), with high values of V indicating low dispersion. It is named after Ernst Abbe (1840–1905), the German physicist ...
Laser sight (firearms) A laser sight is a device attached or integral to a firearm to aid target acquisition. Unlike optical and iron sights where the user looks through the device to aim at the target, laser sights project a beam onto the target, providing a visual reference point. Although lasers in the visible part of the spectrum are most ...
Typically objective lenses on early sights are smaller than modern sights, in these examples the 4×81 would have an objective 36 mm diameter and the 2.5×70 should be approximately 21 mm (relative luminosity is the square of the exit pupil as measured in mm; a 36 mm objective lens diameter divided by the 4× magnification gives an exit pupil ...
An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's performance, such as lens imperfections or aberrations, but these are caused by errors in the manufacture or calculation of a lens, whereas the diffraction limit is the maximum resolution ...
The Advanced Combat Optical Gunsight ( ACOG) is a series of prismatic telescopic sights manufactured by Trijicon. The ACOG was originally designed to be used on the M16 rifle and M4 carbine, but Trijicon has also developed ACOG accessories for other firearms. Models provide fixed-power magnification levels from 1.25× to 6×. [1]
Functions. In contrast to most other eye glasses, shooting glasses usually only have one lens that corrects the ametropia of the dominant eye, which is used for aiming.This lens is selected in such a way that the maximum visual acuity lies on the font sight line element near the muzzle of the (non-magnifying) open type or diopter and globe type match sight line elements to get three points ...
Chromatic aberration. In optics, chromatic aberration ( CA ), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. [1] [2] It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light.
In optics, the Abbe sine condition is a condition that must be fulfilled by a lens or other optical system in order for it to produce sharp images of off-axis as well as on-axis objects. It was formulated by Ernst Abbe in the context of microscopes. [1] The Abbe sine condition says that. the sine of the object-space angle should be proportional ...