PowerPoint presentation in science 10 2nd
- 2. Lenses A lens is made of transparent material such as glass or plastic with a refractive index larger than that of air.
- 3. Two Types of Lenses • A convex lens is thicker at the center than at the edges. Also called converging. A concave lens is thinner at then center than at the edges. Also called diverging.
- 4. Features of Lenses *Principal Plane: the line that passes vertically through the middle of the lens. Principal Axis: the straight line perpendicular to the *Principal Plane of the lens at its center. Focal Point, the location where the parallel rays of light from the source meet, or converge. *Focal Length: the distance from the Focal Point to the Principal Plane along the Principal Axis. *Center of Curvature: twice the distance of the focal point to the mirror surface.
- 5. Finding the Location of Image using Leans *Use ray diagram analysis. *Use mathematical analysis. *The lens equation *The magnification equation *Note that these are identical to those of mirrors.
- 6. Characteristics of Images in a Convex Lens An object beyond 2F will make an image that is REAL, INVERTED, REDUCED. The image is found between F' and 2F (on the other side of the lens). Image information by a converging lens
- 7. Characteristics of Images in a Convex Lens *An object at 2F will make an image that is REAL, INVERTED, SAME SIZE. The image is found at 2F. *An object between F and 2F will make an image that is REAL, INVERTED, ENLARGED. The image is found beyond 2F'.
- 8. Characteristics of Images in a Convex Lens • An object between F and the mirror will make an image that is VIRTUAL, UPRIGHT, ENLARGED. The image is found on the same side of the lens, beyond 2F. Ray diagram of object located in front F
- 9. Characteristics of Images in a Convex Lens An object at F will NOT make an image. Ray diagram of object located in front F
- 10. Summary of the Characteristics of Images in a Convex Lens
- 11. Characteristics of Images in a Concave Lens • Causes light rays to diverge. • Always VIRTUAL, UPRIGHT, REDUCED. • The image is found on the same side of the lens as the object.
- 13. THE PARTS OF CAMERA
- 21. The Compound Microscope • Works very similar to the refracting telescope in that it enlarges small objects. • Uses 2 converging lenses of short focal l
- 22. The Projector • A series of converging lenses are uses to show enlarged images of slides or movies. One set of lenses is used to send intensely bright light through the slide or negatives and a second lens, the projection lens, can be slid back and forth to focus the image.
- 23. *The eye is set up to be a basic lens and receiver of light *The lens bends the light which forms an image so that it inverts at a focal point *The brain compensates for this natural inversion due to the lens, and re-inverts the Image, so that we see properly *The pupil and iris also work optically to change the amount of light flow into the eye, effectively darkening or brightening the image, depending on the amount of light let into the eye