RAY DIAGRAM FOR LENSES

1. TYPES OF LENSES

1.1. Converging lenses causes parallel light rays to come together (i.e. converge) toward a common point.

1.2. Diverging lenses cause parallel rays of light to spread away from a common point (i.e. diverge).

2. INTRODUCTION

2.1. Different types of lenses play an important part in our lives. They are used in cameras, telescopes, microscopes, and projectors. The also enable millions of people to read comfortably and to see clearly.

2.2. Lenses have two sides, and either side can be plane, concave, or convex (i.e. can have two different types of sides). There are many types of lenses, but the ones that we will become familiar with are diverging and converging lenses.

3. EXAMPLE OF CONVERGING LENSES

3.1. Magnifying Glasses-Move the glass farther from the object and it will become distorted; move the glass closer to the object and it will decrease in magnification.

3.2. Eyeglasses-A converging lens placed in front of the eye bends the incoming light sharply so the focal point shortens and the light focuses properly on the retina.In the case of farsightedness, the lens of the eye focuses the image too far behind the retina. This causes difficulty in focusing on objects close to the eye.

3.3. Cameras -utilize converging lenses not only to focus an image but also to magnify it.

4. RULES FOR DIVERGING LENSES:

4.1. Any incident ray traveling parallel to the principal axis of a diverging lens will refract through the lens and travel in line with the focal point (i.e., in a direction such that its extension will pass through the focal point).

4.2. Any incident ray traveling towards the focal point on the way to the lens will refract through the lens and travel parallel to the principal axis.

4.3. An incident ray that passes through the center of the lens will in effect continue in the same direction that it had when it entered the lens.

5. RAY DIAGRAM FOR CONVERGING LENSES

5.1. THE OBJECT IS LOCATED BEYOND 2F

5.1.1. L-BETWEEN F AND 2F,O-INVERTED,S-REDUCED,T-REAL IMAGE

5.2. THE OBJECT IS LOCATED AT 2F

5.2.1. L-AT 2F,O-INVERTED,S-EQUAL,T-REAL IMAGE

5.3. THE OBJECT IS LOCATED BETWEEN 2F AND F

5.3.1. L-BEYOND 2F,O-INVERTED,S-ENLARGED,T-REAL IMAGE

5.4. THE OBJECT IS LOCATED AT F

5.4.1. NO IMAGE FORM

5.5. THE OBJECT IS LOCATED IN FRONT OF F

5.5.1. L-BEHIND THE OBJECT,O-UPRIGHT,S-ENLARGED,T-VIRTUAL IMAGE

6. THANK YOU!!!!

7. RULES FOR CONVERGING LENS:

7.1. Any incident ray traveling parallel to the principal axis of a converging lens will refract through the lens and travel through the focal point on the opposite side of the lens.

7.2. Any incident ray traveling through the focal point on the way to the lens will refract through the lens and travel parallel to the principal axis.

7.3. An incident ray that passes through the center of the lens will in effect continue in the same direction that it had when it entered the lens.

8. DEFINITION OF TERMS:

8.1. Principal axis is a straight line that passes through the centre of the lens, normal to both surfaces of the lens

8.2. A lens is a transparent object with at least one curved side that causes light to refract.

8.3. Converging lens is a lens that converges rays of light that are traveling parallel to its principal axis.Real Images are those where light actually converges,whereis virtual images are locations from where the light appear to have converged.

8.4. Diverging lens is a lens that diverges rays of light that are traveling parallel to its principal axis

9. EXAMPLE OF DIVERGING LENSES

9.1. Binocular and telescope manufacturers therefore install concave lenses in or before the eyepieces to help focus images more clearly for the viewer.

9.2. Flashlights-Concave lenses are used on flashlights to magnify the light produced by the bulb.

9.3. Small concave lenses can widen a laser beam to precisely access a specific area. Concave lenses used with lasers are made from fused silica to withstand the ultraviolet rays produced by the light source.

10. OPTICS EQUATION

10.1. (1/do)+ (1/di) = (1/f) f is positive for Convex (Converging) lenses f is negative for Concave (Diverging) lenses

10.2. Magnification: (hi/ho) = - (di/do) = M

11. RAY DIAGRAM FOR DIVERGING LENSES

11.1. The ray diagrams for concave lenses inside and outside the focal point give similar results: an erect virtual image smaller than the object. The image is always formed inside the focal length of the lens.