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A lens is an optical device that transmits and refracts light. It converges or diverge the beam of light. A single lens consists of a single optical element whereas a compound lens is an array of simple lenses with a common axis. Compound lenses are useful because it allows more optical aberrations to be corrected than is possible with a single element.  Elements which refract electromagnetic radiation outside the visual spectrum are called lenses as well.

Lenses are classified by the curvature of the two optical surfaces. The different types of lenses are listed below in the table:

Biconvex Both surfaces are convex
Plano-convex One surface is concave and the other is convex
Positive meniscus One surface is concave and the other is convex
Negative meniscus One surface is concave and the other is convex
Plano-concave One surface is flat and the other is concave
Biconcave Both surfaces are concave


The focal length of a lens in air is calculated from the lensmaker’s equation below

P = 1/f


P is the power of the lens

f is the focal length of the lens

A Two Lens System

A cell phone of length 10.0cm sits 50.0cm in front of a lens of focal length 30.0cm. a. Without equations, use a diagram to determine whether the image of the cell phone is real or virtual, upright or inverted, and magnified or reduced. Estimate the magnification from your diagram. b. Now calculate the magnification and check

Curvature of the Surface of a Lens

The radii of curvature of the surfaces of a thin lens are +10cm and +30 cm. The index is 1.50. (a) Compute the position and size of the image of an object in the form of an arrow 1 cm high, perpendicular to the lens axis, 40 cm to the left of the lens. (b) A second similar lens is placed 160 cm to the right of the first. Fin

Conflict and Lens Model of Conflict

What contemporary conflict is in the news and what are the mutual interests of both parties in this conflict? What do you see as the incompatible goals in this situation? What are the perceived scarce resources that influence this conflict? What two main destructive patterns, escalatory spirals and avoidance spirals,

Multicultural marketing - what is it and how does this firm use it

PINELLAS PARK, Fla., Sept. 2 /PRNewswire/ -- Recognizing the increased risks African Americans face for a number of eye health issues, Transitions Optical, Inc., the leading supplier of photochromic eyeglass lenses, is launching its "Healthy Sight for Life: Focus on African-American Eyes" campaign at the National Council of Negr

A solution is given to converging lens light.

Please solve and explain Converging lens placed near center of optical bench. Light source and object on left side of lens and screen on the other side. Light source placed as far away from lens as possible (about 39 cm). The screen is moved until image comes into focus on screen. Length of object is 6 cm, d

Converging lens

Please explain the answer to the following: You hold a converging lens in front of a sheet of paper so as to form a sharp image of a distant object or scene from a window. You can use a ruler to measure the focal length of the lens. What would be a likely focal length (estimate). With this focal length, what is the refracti

analyze current competitors

If Bausch and Lomb were to market a polarized contact lens; analyze current competitors and define the competitive landscape for the product. The top three competitors listed on are: Alcon Labs CIBA Vision Corporation Vistakon

Monopolistically Competitive Equilibrium

Soft Lens, Inc., has enjoyed rapid growth in sales and high operating profits on its innovative extended-wear soft contact lenses, However the company faces potentially fierce competition from a host of new competitors assume important basic patents expire during the coming year. Unless the company is able to thwart such comp

Products Liability

I am trying to figure out which rule or law, application and conclusion can be drawn here. I have posted a case as an example. I read that it was settled for monetary amount. See below. National Plaintiffs' Management Committee prosecuting Roberts v. Bausch & Lomb, Inc. (Decided by U.S. District Court, Northern District of

Galilean Telescope

Consider a Galilean telescope, as illustrated in Figure 27-23, constructed from two lenses with focal lengths of 70.8 cm and -15.7 mm. Please see attached.


Hi. Can someone please show me how to do the following problem? Thank you. "The Moon has an angular size of 0.50° when viewed with unaided vision from Earth. Suppose the Moon is viewed through a telescope with an objective whose focal length is 51 cm and an eyepiece whose focal length is 51 mm. What is the angular size of th

Lenses/Compound Microscope

Hi. Can someone please show me how to do the following problem? Thank you. "A compound microscope has the objective and eyepiece mounted in a tube that is 18.0 cm long. The focal length of the eyepiece is 2.28 cm, and the near-point distance of the person using the microscope is 25.0 cm. If the person can view the image produ

Converging Lenses

A converging lens has a focal length of 30 cm. An object that is 20 cm tall is placed 45 cm from the lens. 1. What is the image distance? a. 45 cm, other side of lens b. 20 cm, same side of lens c. 100 cm, other side of lens d. 30 cm, same side of lens 2. Is the image upright or up-side-down?

What is the height (including sign) of her image on the film

A camera is supplied with two interchangeable lenses, whose focal lengths are 35.0 and 150.0 mm. A woman whose height is 1.80 m stands 7.00 m in front of the camera. What is the height (including sign) of her image on the film, as produced by a 35.0-mm and 150.0-mm lens?

Macro lens distance

A macroscopic (or macro) lens for a camera is usually a converging lens of normal focal length built into a lens barrel that can be adjusted to provide the additional lens-to-film distance needed when focusing at very close range. Suppose that a macro lens (f = 53.0 mm) has a maximum lens-to-film distance of 271 mm. How close ca

Find the location of the image and its character

A convex lens of focal length 7.5 cm is placed 12 cm to the left of a convex lens with a focal length of 6.5 cm. An object is placed 10.0 cm to the left of the lens with a focal length of 7.5 cm. Find the location of the image and its character (e.g., real, inverted) (A ray diagram may prove to be helpful also). Thank you

Use natural deduction to derive the conclusion of each argument.

---------------------------------------------- DIRECTIONS FOR TRANSLATIONS Translate the following statements into symbolic form. Use the letters O, C, M, P, R, N, and L as needed. Use (> for horseshoe) (* for dot)(v wedge)(=tripple bar)(~tilde) ----------------------------------------------- 1. Nikon will introduce a new