By: Liz and Sabrina

W HAT IS A LENS ? A lens is a transparent optical device used to converge or diverge transmitted light and to form images.

M IRRORS ? S AY WHAT ? A mirror is an object with at least one polished and therefore specularly reflective surface. The most familiar type of mirror is the plane mirror, which has a flat surface. Curved mirrors are also used, to produce magnified or diminished images or focus light or simply distort the reflected image.

T YPES OF M IRRORS Plane Mirrors A plane mirror has even surfaces. The normal is a line perpendicular to all points of a plane mirror. The angle of incidence is an angle that light hits the mirror relative to the normal. The angle of reflection is an angle of that light's reflection, on the other part of the normal, and is equal to the angle of incidence. The image seen in a plane mirror seems to be behind the mirror. This is an example of a virtual image It is also right-side up, but reversed from right to left. This can be seem noticeably by holding up a word to a plane mirror. The letters would each be flipped and the order of the word would be reversed.

S PHERICAL M IRRORS A curved mirror is a mirror with a curved reflective surface, which may be either convex (bulging outward) or concave (bulging inward)

E QUATIONS Here are equations that analytically explain the image results. The focal length of a spherical mirror: The spherical mirror equation: The magnification equation for a spherical mirror:

EQUATIONS Where M is the magnification factor s object is distance from object to the mirror, s image is the distance from the image to the mirror, f is focal length, and R is radius of curvature.magnification factorradius of curvature

T YPES OF L ENSES Two types of lenses are biconvex lenses, which are converging lenses and biconcave lenses, which are diverging lenses. Converging lenses are thicker in the center than at the edges, while diverging lenses are thicker at the edges that in the center.converging lenses diverging lenses

C ONVERGING LENSES Convex or converging lenses can form real or virtual images: When the light enters in parallel rays, the light is concentrated on one point-the focal point. When the light enters from an object that is further away from the lens that the focal length, the light is concentrated on one point where a real image is produced. When the light enters from an object that is closer to the lens than the focal length, the light diverges, as to seem to have come from behind the lens, forming a virtual image. When the light enters from the lens’ focal point, the lens makes the light a parallel beam.

D IVERGING L ENSES Concave or diverging lenses produce virtual images. The light rays appear to diverge from the virtual image on the side of the lens with the object.

L ENS E QUATION Thins Lens Equation: OR Magnification equation with a thin lens:

D IFFERENT U SES OF L ENSES An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors.

D IFFERENT U SES OF L ENSES Binoculars, field glasses or binocular telescopes are a pair of identical or mirror- symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects.

D IFFERENT U SES OF L ENSES A microscope is an instrument to see objects too small for the naked eye. Optical microscopes have refractive glass and occasionally of plastic or quartz, to focus light into the eye or another light detector.

D IFFERENT U SES OF L ENSES A camera is a device that records images. These images may be still photographs or moving images such as videos or movies. A majority of cameras have a lens positioned in front of the camera's opening to gather the incoming light and focus all or part of the image on the recording surface.

T EST T IME =) What are the 2 types of lenses? a. converging and diverging b. concave and spherical What are the 2 types of mirrors? A. plane and converging B. plane and spherical One common use of a lens? A. camera B. microwave C. computer D. chairs A curved mirror with a curved reflective surface is either: A. convex or concave b. converging or spherical What is the most common type of mirror? A. square b. circular c. spherical d. plane In the lens equations, what does M stand for? A. multiply b. magnitude c. magnification factor d. mirror

A NSWERS What are the 2 types of lenses? a. converging and diverging b. concave and spherical What are the 2 types of mirrors? A. plane and converging B. plane and spherical One common use of a lens? A. camera B. microwave C. computer D. chairs A curved mirror with a curved reflective surface is either: A. convex or concave b. converging or spherical What is the most common type of mirror? A. square b. circular c. spherical d. plane In the lens equations, what does M stand for? A. multiply b. magnitude c. magnification factor d. mirror

L ENS & M IRRORS ( OPTICS ) By: Grace Garcia & Tyler Noone

I NTRO Lenses and mirrors play important roles in our daily lives even though we may not notice them.

P LANE MIRRORS  A plane¹ mirror has even surfaces.  The normal is a line perpendicular to all points of a plane mirror.  The angle of incidence is an angle that light hits the mirror relative to the normal.  The angle of reflection is an angle of that light's reflection, on the other part of the normal, and is equal to the angle of incidence.  The image seen in a plane mirror seems to be behind the mirror.

PLANE MIRRORS CONTINUED  This is an example of a virtual image  It is also right-side up, but reversed from right to left.  This can be seem noticeably by holding up a word to a plane mirror.  The letters would each be flipped and the order of the word would be reversed.  To determine the size of an image seen through a plane mirror, the following equation is used:

S PHERICAL MIRRORS  A spherical² mirror is a mirror in the form of a slice of a spherical surface.  A convex³ mirror is curved outward, like the outside of a sphere.  When parallel light rays pass through a convex mirror, the reflected light appears to have come from behind, hence making it a virtual image.  Because the rays reflected from a convex mirror diverge from any length, a diverging mirror will always produce a virtual image.  This explains why the passenger side mirrors of cars, which are convex mirrors, display objects that look smaller than they are: the brain considers the diverging rays to have come from an image behind the mirror itself.  A concave mirror curves inward like the hollow inside of a sphere.

S PHERICAL M IRRORS C ONTINUED  Or, in other words, it appears "caved-in", which could help you differentiate from both spherical mirrors.  The light hitting the surface of concave mirror converges, and the image made by the mirror is either virtual or real, depending on the position of the object that is reflected.  If the object is between the mirror and the focus, it will be right side up, virtual, and larger, while objects farther than the focus will be real images that subject to the position once again, may appear upside-down, larger, or smaller.

S PHERICAL M IRROR E QUATIONS  Here are equations that analytically explain the image results discussed in the previous section.  Where M is the magnification factor, s object is the distance from the object to the mirror, s image is the distance from the image to the mirror, f is the focal length, and R is the radius of curvature.

S PHERICAL M IRROR E QUATIONS C ONTINUED  The focal length of a spherical mirror:  The spherical mirror equation:  The magnification equation for a spherical mirror:

L ENSES An optical lens is made from see-through materials and is generally spherical in shape.

T YPES OF L ENSES  Two types of lenses are biconvex lenses, which are converging lenses and biconcave lenses, which are diverging lenses.  Converging 6 lenses are thicker in the center than at the edges, while diverging lenses are thicker at the edges that in the center.

T YPES OF L ENSES C ONTINUED  Convex or converging lenses can form real or virtual images:  When the light enters in parallel rays, the light is concentrated on one point-the focal point.  When the light enters from an object that is further away from the lens that the focal length, the light is concentrated on one point where a real image is produced.  When the light enters from an object that is closer to the lens than the focal length, the light diverges, as to seem to have come from behind the lens, forming a virtual image.  When the light enters from the lens’ focal point, the lens makes the light a parallel beam.

L ENS E QUATIONS  Thins Lens Equation: OR  Magnification equation with a thin lens:

T EST 1. A _________ mirror has even surfaces. 2. A _________ mirror is a mirror in the form of a slice of a spherical surface. 3. A __________ mirror is curved outward, like the outside of a sphere. 4. A ___________ mirror curves inward like the hollow inside of a sphere. 5. An _________ lens is made from see-through materials and is generally spherical in shape. 6. ___________ lenses are thicker in the center than at the edges, while diverging lenses are thicker at the edges that in the center.