Instruction Guide: Elementary Optics and Applications to Fire Control InstrumentsU.S. Government Printing Office, 1945 - 211 σελίδες |
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Σελίδα 29
... FOCAL LENGTH AND FOCAL PLANE . a . Focal Point of Convergent Lens . When light strikes and passes through a convergent lens , the rays from a point of light inter- sect at a point on the opposite side of the lens . The point at which ...
... FOCAL LENGTH AND FOCAL PLANE . a . Focal Point of Convergent Lens . When light strikes and passes through a convergent lens , the rays from a point of light inter- sect at a point on the opposite side of the lens . The point at which ...
Σελίδα 30
... focal length of the lens . The thicker the lens in relation to its size , or the steeper the curves of the lens , the shorter its focal length will be . d . The focal plane of the lens ( fig . 44 ) is a thin , flat area at right angles ...
... focal length of the lens . The thicker the lens in relation to its size , or the steeper the curves of the lens , the shorter its focal length will be . d . The focal plane of the lens ( fig . 44 ) is a thin , flat area at right angles ...
Σελίδα 31
United States. War Department. Properties of Light POINT OF PRINCIPAL FOCUS OPTICAL CENTER POINT OF PRINCIPAL FOCUS FOCAL LENGTH- FOCAL LENGTH- RA PD 102536 Figure 44 Focal Lengths of Convergent Lens a . Magnification is the apparent ...
United States. War Department. Properties of Light POINT OF PRINCIPAL FOCUS OPTICAL CENTER POINT OF PRINCIPAL FOCUS FOCAL LENGTH- FOCAL LENGTH- RA PD 102536 Figure 44 Focal Lengths of Convergent Lens a . Magnification is the apparent ...
Σελίδα 32
United States. War Department. Properties of Light POINT OF PRINCIPAL FOCUS . FOCAL LENGTH RA PD 30252 b . Multiple lenses ( par . 64 ) may be used to correct for color and other faults . A theoretically perfect single lens is assumed in ...
United States. War Department. Properties of Light POINT OF PRINCIPAL FOCUS . FOCAL LENGTH RA PD 30252 b . Multiple lenses ( par . 64 ) may be used to correct for color and other faults . A theoretically perfect single lens is assumed in ...
Σελίδα 33
... focal length , there is no real image because the rays are parallel after re- fraction ; the image is said to be at ... focal length of a convergent lens , the image will be on the same side of the lens as the object , magnified and ...
... focal length , there is no real image because the rays are parallel after re- fraction ; the image is said to be at ... focal length of a convergent lens , the image will be on the same side of the lens as the object , magnified and ...
Συχνά εμφανιζόμενοι όροι και φράσεις
ABBE PRISM achromatic adjustment Amici prism angle of incidence astigmatism axis azimuth binocular chromatic aberration Coated Optics collective lens color compound lens concave Construction Features convergent lens convex critical angle crown glass curvature deviation diopter divergent lens Elbow Telescope ERECTOR exit pupil eyepiece field of view Figure filters Fire Control Instruments flint glass focal length focal plane focal point focusing Glossary height finder horizontal incident ray index of refraction inverted lens erecting system lenses light rays line of sight magnification medium mils mirror mounted normal objective prism observer Optical Components Optical Diagram optical elements optical instrument optical system Panoramic Telescope parallel path of light penta prism periscope point of light PORRO PRISM prism erecting system Properties of Light RA PD range finder rays of light real image reflected ray reflecting surface Representative Fire Control reticle retina right angles spherical aberration stereoscopic target vision wave length yards
Δημοφιλή αποσπάσματα
Σελίδα 181 - When a ray of light passes from one medium to another, it is refracted so that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the velocities in the two media.
Σελίδα 6 - BY ORDER OF THE SECRETARY OF WAR: GC MARSHALL, Chief of Staff. OFFICIAL: JA ULIO, Major General, The Adjutant General.
Σελίδα 12 - ... which struck the water, that is to say the angle of reflection will be equal to the angle of incidence.
Σελίδα 188 - Usually a thin coating of silver or aluminum on glass constitutes the actual reflecting surface. When this surface is applied to the front face of the glass, the mirror is termed a front surface mirror.
Σελίδα 186 - The magnifying power of the telescope is equal to the quotient of the focal length of the objective divided by the focal length of the ocular.
Σελίδα 148 - Each degree is divided into 60 parts called minutes, and each minute into 60 parts called seconds.
Σελίδα 89 - A filter is usually of special glass, gelatin, or plastic optical parts with plane parallel surfaces that are placed in the path of light through the optical system of an instrument to selectively absorb certain wavelengths of light, reduce glare, or reduce light intensity. Colored, ultraviolet, neutral density, and polarizing filters are in common use. Filters may be separate elements or integral devices mounted so that they can be placed in or out of position in...
Σελίδα 16 - The plane which contains the incident and reflected rays and the normal to the surface is called the plane of incidence, the angle between the incident ray and the normal is the angle of incidence...
Σελίδα 182 - The index of refraction expressed in tables is the absolute index, that is, vacuum to substance at a certain temperature, with light of a certain wavelength. Examples, vacuum, 1.000; air, 1.000292; water, 1.333; ordinary crown glass, 1.516. Since the index of air is very close to that of vacuum, the two are often used interchangeably.
Σελίδα 181 - Descartes notices — and this seems to be the first step in the reduction — that "the determination of this [anaclastic] line depends on the relation between the angle of incidence and the angle of refraction