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The Lenses and Refraction ClipArt gallery offers 75 illustrations of light changing direction as it passes through media with different refractive indices.

"In <em>optics</em>, a deviation in the rays of light when unequally refracted by a lens or reflected by a mirror, so that they do not converge and meet in a point or focus, but separate, forming an indistinct image of the object, or an indistinct image with prismatically colored edges."-Wright, 1902

Aberration

"In optics, a deviation in the rays of light when unequally refracted by a lens or reflected…

A cut of a gemstone. A brilliant cut stone has fifty-eight facets.

Brilliant Cut

A cut of a gemstone. A brilliant cut stone has fifty-eight facets.

"Catadioptric Fixed Light.—This apparatus, in which a central burner is used, consists of a dioptric cylindric refractor with zones of silvered mirror above and below similar in profile to Bordier Marcet's reflector. By the adoption of the refractor the whole of the wasteful divergence which occurs in Marcet's reflector is prevented. We have here a geometrically perfect combination, but it is not so physically, because metallic reflexion is used. This physical defect Fresnel obviated in his next design." —The Encyclopedia Britannica, 1910

Catadiopteric Light

"Catadioptric Fixed Light.—This apparatus, in which a central burner is used, consists of a dioptric…

"Catadioptric Holophote.—Part of the anterior hemisphere of rays is intercepted and at once parallelized by the lens L, whose principal focus (i.e., for parallel rays) is in the center of the flame, while the remainder is intercepted and made parallel by the paraboloid a, and thus the double agents in Fresnel's design are dispensed with. The rays of the posterior hemisphere are reflected by the spherical mirror b back again through the foxus, whence passing onwards one portion of them falls on the lens and the rest on the paraboloid, so as finally to emerge in union with and parallel to the front rays." —The Encyclopedia Britannica, 1910

Catadioptric Holophote

"Catadioptric Holophote.—Part of the anterior hemisphere of rays is intercepted and at once parallelized…

"Because of their greater refrangibility, the focus of the violet rays is nearer the lens than the focus of the red rays, as illustrated. If the screen is as near the lens as the focus marked v, the outer fringe is red. If the screen is as far from the lens as the focus marked r, the outer fringe is violet. This difference in the deviation of differently colored rays is called chormatic aberration." -Avery 1895

Chromatic Aberration

"Because of their greater refrangibility, the focus of the violet rays is nearer the lens than the focus…

"Condensing Apparatus for Steamer's Side Lights.—By means of this application of the condensing principle all the light can be distributed with strict equality over 112 degrees, which is the arc prescribed for steamers by the Board of Trade. Several of the Transatlantic and other steamers have adopted this kind of apparatus, which is hung on gimbals and placed in iron towers, having an entry from below the deck, which can be made use of in bad weather." —The Encyclopedia Britannica, 1910

Condensing Apparatus

"Condensing Apparatus for Steamer's Side Lights.—By means of this application of the condensing principle…

"Fixed Conensing Light for a Single Sector, 1850.—The holophote Light pLp throws its whole light on straight condensing prisms c, each of which distributes the rays over the required sector." —The Encyclopedia Britannica, 1910

Condensing Light

"Fixed Conensing Light for a Single Sector, 1850.—The holophote Light pLp throws its whole light on…

"Condensing Octant.—The central fixed apparatus bb with spherical mirror dd throws its rays directly over the angle of 45 degrees pgp, while the supplemental rays fall upon the straight condensing prisms p, each of which spreads the incident rays parallel to the corresponding rays in the central angle pgp. In this way the whole of the front hemisphere of rays is parallelized in the vertical plane and spread equally over the 45 degree in azimuth." —The Encyclopedia Britannica, 1910

Condensing Octant

"Condensing Octant.—The central fixed apparatus bb with spherical mirror dd throws its rays directly…

"Condensing Octant.—The central fixed apparatus bb with spherical mirror dd throws its rays directly over the angle of 45 degrees pgp, while the supplemental rays fall upon the straight condensing prisms p, each of which spreads the incident rays parallel to the corresponding rays in the central angle pgp. In this way the whole of the front hemisphere of rays is parallelized in the vertical plane and spread equally over the 45 degree in azimuth." —The Encyclopedia Britannica, 1910

Condensing Octant

"Condensing Octant.—The central fixed apparatus bb with spherical mirror dd throws its rays directly…

"Condensing Quadrant.—The fixed apparatus bbb, with spherical mirror behind, throws its rays directly through the angle of 90 degrees afa', while the supplementary rays falling on the straight condensing prisms p, p, p', p' are sent out parallel to the corresponding rays in the unobstructed central quadrant of the main apparatus. The whole light will therefore be condensed equally over 90 degrees." —The Encyclopedia Britannica, 1910

Condensing Quadrant

"Condensing Quadrant.—The fixed apparatus bbb, with spherical mirror behind, throws its rays directly…

"A modification of the simple kaleidoscope was introduced by Sir David Brewster, whereby the images of large and distant objects can be introduced into the picture. This is effected by removing the object box and replacing it by a tube carrying at its outer end a double convex lens, represented by LL. By a screw adjustment the lens can be so placed as to focus the distant object exactly in the plane of the sector AOB, and so bring its image into the very best position for producing symmetrical patterns. When this instrument is directed towards a tree in full bloom, a very beautiful effect is produced, which can be varied by gradually moving the instrument. This form was called by Brewster the telescopic kaleidoscope." —The Encyclopedia Britannica, 1910

Convex Lens

"A modification of the simple kaleidoscope was introduced by Sir David Brewster, whereby the images…

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup, with a shilling on the bottom, in such a position that the side of the cup will just hide the piece of money from the eye. Then let another person fill the cup with water, keeping the eye in the same position as before. As the water is poured in, the shilling will be come visible, appearing to rise with the water. The effect of the water is to bend the ray of light coming from the shilling, so as to make it meet the eye below the point where it otherwise would. Thus the eye could not see the shilling in the direction of c, since the line, of vision is towards a, and c is hidden by the side of the cup. But the refraction of the water bends the way downwards, producing the same effect as though the object had been raised upwards, and hence it becomes visible." &mdash;Comstock, 1850

Cup and Shilling

"The refraction of water is beautifully proved by the following simple experiment. Place an empty cup,…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius…

"Perfect Form of Dioptric Holophote for an Oil Flame.—By combining the back prisms ga, hc just described with a semi-holophote abc subtending 180 degrees and a portion of the dioptric spherical mirror ijk, no light is lost on the burner, and all the rays are parallelized, so that this apparatus, being all of glass, is both geometrically and physically perfect." —The Encyclopedia Britannica, 1910

Dioptric Holophote

"Perfect Form of Dioptric Holophote for an Oil Flame.—By combining the back prisms ga, hc just described…

"First Application of Total Reflexion to Fixed Lights. In this apparatus Fresnel substituted his totally reflecting prism p and lens R for Marcet's reflector, and thus distributed the whole light equally over the horizon by means of dioptric agents alone. This was the first application of total reflexion to lighthouse apparatus, and this beautiful instrument continues till now in universal use." —The Encyclopedia Britannica, 1910

Dioptric Light

"First Application of Total Reflexion to Fixed Lights. In this apparatus Fresnel substituted his totally…

"Dioptric Floating Light. Elevation." —The Encyclopedia Britannica, 1910

Dioptric Light

"Dioptric Floating Light. Elevation." —The Encyclopedia Britannica, 1910

"Dioptric Floating Light. Horizontal Section." —The Encyclopedia Britannica, 1910

Dioptric Light

"Dioptric Floating Light. Horizontal Section." —The Encyclopedia Britannica, 1910

This illustration shows a Double Brilliant (sometimes called Lisbon) cut gem.

Double Brilliant Cut

This illustration shows a Double Brilliant (sometimes called Lisbon) cut gem.

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular lenses L, and a compound arrangement of inclined trapezoidal lenses L' and plane silvered mirrors M. The inclined lenses fit closely to each other and form a pyramidal dome, and the light, intercepted by them, is sent upwards in inclined beams until, falling upon the plane mirrors M, it is sent outwards in horizontal parallelized beams. All these optical agents are made to revolve round the central lamp, and the sailor receives a full flash when the axis of one of the emerging beams passes his eye, and as soon as it passes him he is in darkness until the next beam comes round." —The Encyclopedia Britannica, 1910

Fresnels Revolving Light

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular…

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular lenses L, and a compound arrangement of inclined trapezoidal lenses L' and plane silvered mirrors M. The inclined lenses fit closely to each other and form a pyramidal dome, and the light, intercepted by them, is sent upwards in inclined beams until, falling upon the plane mirrors M, it is sent outwards in horizontal parallelized beams. All these optical agents are made to revolve round the central lamp, and the sailor receives a full flash when the axis of one of the emerging beams passes his eye, and as soon as it passes him he is in darkness until the next beam comes round." —The Encyclopedia Britannica, 1910

Fresnels Revolving Light

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular…

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular lenses L, and a compound arrangement of inclined trapezoidal lenses L' and plane silvered mirrors M. The inclined lenses fit closely to each other and form a pyramidal dome, and the light, intercepted by them, is sent upwards in inclined beams until, falling upon the plane mirrors M, it is sent outwards in horizontal parallelized beams. All these optical agents are made to revolve round the central lamp, and the sailor receives a full flash when the axis of one of the emerging beams passes his eye, and as soon as it passes him he is in darkness until the next beam comes round." —The Encyclopedia Britannica, 1910

Fresnels Revolving Light

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular…

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular lenses L, and a compound arrangement of inclined trapezoidal lenses L' and plane silvered mirrors M. The inclined lenses fit closely to each other and form a pyramidal dome, and the light, intercepted by them, is sent upwards in inclined beams until, falling upon the plane mirrors M, it is sent outwards in horizontal parallelized beams. All these optical agents are made to revolve round the central lamp, and the sailor receives a full flash when the axis of one of the emerging beams passes his eye, and as soon as it passes him he is in darkness until the next beam comes round." —The Encyclopedia Britannica, 1910

Fresnels Revolving Light

"Fresnel's Revolving Light. —In this form of revolving light the central burner is surrounded by annular…

"Holophotal Catadioptric Apparatus Revolving round a Central Flame.—If in place of Fresnel's compound arrangement of trapezoidal lenses and plane mirrors there are substituted mirrors R, R generated by the revolution of a parabolic profile round a horizontal axis, all the light will be at once sent out in parallel beams by them and the lenses L, and the apparatus is therefore geometrically perfect, but metallic instead of glass agents are still employed." —The Encyclopedia Britannica, 1910

Holophotal Catadioptric

"Holophotal Catadioptric Apparatus Revolving round a Central Flame.—If in place of Fresnel's compound…

"Holophotal Fixed Light varied by Flashes.—Fresnel's double agents are here also dispensed with by the single agency of panels of fixed light apparatus p', p' and cylindrical refractors L', L', alternating with panels of holophotal apparatus p, p, L, L, both of which revolve together round the central burner." —The Encyclopedia Britannica, 1910

Holophotal Light

"Holophotal Fixed Light varied by Flashes.—Fresnel's double agents are here also dispensed with by…

Bernieres Immense Burning Glass is an illustration found in an illustrated journal The "Wonders of Heat" by Achille Cazin. This drawing shows the phenomenon of burning glass to produce heat.

Bernieres Immense Burning Glass

Bernieres Immense Burning Glass is an illustration found in an illustrated journal The "Wonders of Heat"…

"A lens is a transparent body the two refracting surfaces of which are curved, or one of which is curved and the other plane.(1) Double convex(2) Plano convex(3) Meniscus(4)Double concave(5) Plano concave(6) Concavo concave." -Avery 1895

Lens

"A lens is a transparent body the two refracting surfaces of which are curved, or one of which is curved…

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more than the blue; and as the objective gives a large blue and small red image, the two cancel one another and a colourless image is produced." &mdash;Encyclopaedia Britannica, 1910

Huyegenian Eyepiece Diagram Showing Lens Refraction

"They have also a shorter focus for red, and a longer one for blue, and thus magnify the red image more…

"If the real image produced by the objective coincides with the collective lens, only the inclination of the principal rays is altered. The lens nearer to the eye is distant from it about its focal length. The eye&mdash;lens converts diverging pencils into parallels. Both lenses together form the exit pupil of the objective behind the eye&mdash;lens." &mdash;Encyclopaedia Britannica, 1910

Ramsden Eyepiece Lens Refraction Diagram

"If the real image produced by the objective coincides with the collective lens, only the inclination…

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to overcome the dispersive effect for some of the colors without overcoming the converging effect." -Avery 1895

Achromatic Lens

"A double convex lens of crown-glass may be combined with a plano-convex lens of flint-glass so as to…

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident ray." -Avery 1895

Refraction of Light through Bi Convex Lens

"...let LN represent a glass biconvex lens, with centres of curvature at C and C', and AB, the incident…

"When the object is at a long distance from the lens, the image formed is smaller than the object, and inverted." -Foster, 1921

Convex Lens

"When the object is at a long distance from the lens, the image formed is smaller than the object, and…

"The shape of the double convex lens, d, c, is that of two plano-convex lenses, placed with their plane surfaces in contact, and consequently the focal distance of this lens is nearly the centre of the sphere of which one of its surfaces is a part." -Comstock 1850

Double Convex Lens

"The shape of the double convex lens, d, c, is that of two plano-convex lenses, placed with their plane…

"Double convex lenses are used in the eyeglasses for old people, becoming more spherical according to the age of the person or the magnifing power required." -Comstock 1850

Double Convex Lens Magnifing an Arrow

"Double convex lenses are used in the eyeglasses for old people, becoming more spherical according to…

"The double convex lens may be described as the part common to two spheres that intersect each other. The centers of the limiting spherical surfaces, as c and C, are the centers of curvature. The straight line, XY, passing through the centers of curvature is the principal axis of the lens." -Avery 1895

Double Convex Lens

"The double convex lens may be described as the part common to two spheres that intersect each other.…

"Thus the pencils of converging rays, are rendered still more convergent by their passage through the lens, and are therefore brought to a focus nearer the lens, in proportion to their previous convergency." -Comstock 1850

Converging Rays and a Double Convex Lens

"Thus the pencils of converging rays, are rendered still more convergent by their passage through the…

"If diverging rays fall on the surface of the same lens, they will, by refraction, be rendered less divergent, parallel, or convergent, according to the degrees of their divergency, and the convexity of the surface of the lens." -Comstock 1850

Diverging Rays from a Double Convex Lens

"If diverging rays fall on the surface of the same lens, they will, by refraction, be rendered less…

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light; O'" for blue. The system is under—corrected for red, and over—corrected for blue rays." —Encyclopaedia Britannica, 1910

Light Correction of Blue and Red Lights using Spherical Lens

"Showing a system with chromatic difference of spherical aberration. O" ₌ image of O for red light;…

"If the whole circle be considered the circumfrence of a sphere, of which the plano-convex lens b, a, is a section, then the focus of parallel rays, or the principal focus, will be at the opposite side of the sphere, or at c." -Comstock 1850

Plano Convex Lens

"If the whole circle be considered the circumfrence of a sphere, of which the plano-convex lens b, a,…

"View of an arrow through a plano convex lens will have the arrow appear smaller than it actually is." -Comstock 1850

View of an Arrow Through a Plano Convex Lens

"View of an arrow through a plano convex lens will have the arrow appear smaller than it actually is."…

"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave; g, plano-concave; h, meniscus; i, concavo-convex lenses." -Comstock 1850

Lenses of Various Forms

"a, prism; b, plane glass; c, spherical lens; d, double-convex; e, plano-convex, f, double-concave;…

"The lens is spherically corrected for OO', but the sinecondition is not fulfilled. Hens the different magnifications of a point O1 beyond the axis." —Encyclopaedia Britannica, 1910

Magnification of Image Beyond Axis with Lens

"The lens is spherically corrected for OO', but the sinecondition is not fulfilled. Hens the different…

"BA is the ray of light passing through a rare medium (as, for instance, air); and upon its entrance into a denser medium (as, for instance, water) the ray will be deflected from the direction of its path BA, and will take the course AE. If the line CD is perpendicular to the dividing surface between the two media, then BAC is the angle of incidence and DAE is the angle of refraction." -Waldo, 1896

Atmospheric Optics

"BA is the ray of light passing through a rare medium (as, for instance, air); and upon its entrance…

The figure "illustrates the bending of the solar rays entering the atmosphere. When the sun is below the horizon, at C, it would be invisible at A, on account of the curvature of the earth, if there were no atmosphere; but the solar rays entering the atmosphere near the point B are refracted so that they reach A, and the sun appears to be at D, though really at C below the horizon, either in the morning or in the evening. So that, in the polar regions, the sun is visible while it is in reality below the horizon, and is thus seen earlier and later during the time of polar sunlight." -Waldo, 1896

Atmospheric Optics

The figure "illustrates the bending of the solar rays entering the atmosphere. When the sun is below…

The halo phenomena is illustrated in this diagram.

Atmospheric Optics

The halo phenomena is illustrated in this diagram.

"If y be the object the image appears to a normal eye situated behind the system L with passive accommodation at a very great distance under the angle w'. Since H' P= F O, = y, from the focal length of the simple microscope is the image side focal length." —Encyclopaedia Britannica, 1910

Optical Position and Size of Image Through Magnifying Glasses

"If y be the object the image appears to a normal eye situated behind the system L with passive accommodation…

Double Porro prism systems are used in small optical telescopes to re-orient an inverted image, and especially in many binoculars where they both erect the image and provide a longer, folded distance between the objective lenses and the eyepieces.

Porro Prism

Double Porro prism systems are used in small optical telescopes to re-orient an inverted image, and…

"A prism is a transparent body with two refraction surfaces that lie in intersecting planes. The angle formed by these planes is called the refracting angle." -Avery 1895

Prism

"A prism is a transparent body with two refraction surfaces that lie in intersecting planes. The angle…

"The following simple experiment illustrates the effect of refraction:&mdash;Place a silver coin, m, at the bottom of the basin. The rays, i i, proceeding to the eye from the silver surface, render the coin visible. The point a, the eye, is then moved farther bck, so that the edge of the basin obstructs the direct rays, and of course the coin is no longer seen. If an attendant carefully pours water into the basin, so that the object is not moved, it will presently, as the water rises in the basin, become again visible. This arises from the refraction of the rays by the water, the image, indeed, appearing at n instead of at m." &mdash;Wells, 1857

Refraction

"The following simple experiment illustrates the effect of refraction:—Place a silver coin, m,…

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction." &mdash;Croft 1917

Refraction of Light through Glass

"Illustrating refraction of light from a source through glass, and the appropriate angles of refraction."…

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the end B in the direction of the refracted ray, and it appears at D instead of where it really is." -Foster, 1921

Refraction

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the…

"Since air is a rarer medium and water is denser, as ray A passes into the water, it is refracted to C. Also note that as ray B leaves the water, it is refracted to D as it enters the air." &mdash;Quackenbos 1859

Refraction Between Mediums

"Since air is a rarer medium and water is denser, as ray A passes into the water, it is refracted to…

"Although a ray of light will pass in a straight line, when not interrupted, yet when it passes obliquely from one transparent body into another, of a different density, it leaves its linear direction, and is bent, or refracted more or less, out of its former course." -Comstock 1850

Refraction of Light

"Although a ray of light will pass in a straight line, when not interrupted, yet when it passes obliquely…

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular direction." -Comstock 1850

Refraction, air, water, glass

"Let a represent a, b water, and c a piece of glass. The ray d, striking each medium in a perpendicular…

"Showing how an object is refracted through a biconvex lens." -Avery 1895

Object Refracted through Biconvex Lens

"Showing how an object is refracted through a biconvex lens." -Avery 1895

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two surfaces are equal and contrary in direction. The direction after passing through the plate is parallel to the direction before entereing the plate; the rays merely suffer lateral aberration." -Avery 1895

Refraction by Plates

"When radiant energy passes through a medium bounded by parallel planes, the refractions at the two…

"The prism will deflect the red and orange, and form a reddish colored image at n. The violet, indigo, blue, green and yellow light, not caught by the prism, will unite at f to form a greenish image. When the prism is removed, the reddish light that fell at n, and the greenish light that fell at f, unite to form white light." -Avery 1895

Refraction of Complimentary Colors

"The prism will deflect the red and orange, and form a reddish colored image at n. The violet, indigo,…

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the molecules of the glass, and impart some of their motion to those molecules' i.e., a part of the light is absorbed. When a beam of light, as represented by ABC moves forward in the air, the wave-front, MN, continues parallel to itself and moves forward in a straight line. As the wave front advances, A strikes the glass first, and is retarted, the retardation of B and C later change the direction of the rays." -Avery 1895

Explanation of Refraction

"Thus, when erher waves that constitute light are transmitted through glass, they are hindered by the…

"Illustration depicting the refraction by the eye." -Comstock 1850

Refraction by the Eye

"Illustration depicting the refraction by the eye." -Comstock 1850