1. LENS APPLICATIONS 13.5 – PG. 567 to 570

2. TYPES OF LENS APPLICATIONS The Camera The Movie Projector

3. TYPES OF LENS APPLICATIONS The Magnifying Glass The Compound Microscope The Refracting Telescope

4. THE CAMERA Produces a smaller, real image Acts like converging lens, producing an inverted, real image as long as the object is at a distance greater then F’ (secondary principal of focus) Takes light from large, distant objects and forms smaller, real images on film or the sensor in a digital camera Digital cameras use a light-sensitive device made of silicon called a charge-coupled device (CCD), which replaces the film found in traditional cameras How do Digital Cameras Work http://www.youtube.com/watch?v=9dXlok8PMLo

5. THE MOVIE PROJECTOR A movie projector acts like the opposite of a camera Projectors take a small object (film) and projects a large, inverted, real image on the screen The image is larger than the object, meaning the film must be located between F’ and 2F’ Film must be loaded into the projector upside down so that what you see on the movie screen is upright Overhead projectors work in a similar way How a Movie Projectors Works http://www.youtube.com/watch?v=Ca_4dN8jrbg

6. THE MAGNIFYING GLASS The simplest optical device is the magnifying glass, also known as a simple microscope It is a converging lens, where the object is located between F’ and the lens and does not produce a real image at the object location Refracted rays spread apart or diverge, creating a larger, upright, virtual image on the same side of the lens as the object The human brain extends these rays backwards and produces an enlarged, virtual image located on the same side of the lens as the object Giant Magnifying Glass http://www.youtube.com/watch?v=ljiTNRiLh-o

7. THE COMPOUND MICROSCOPE An arrangement of two converging lenses that produces two enlarged, inverted images: one real and one virtual The real image is formed by the objective lens and appears in the body tube of the microscope, therefore you do not actually see this image The virtual image is formed by the eyepiece lens; this larger, virtual image is the image you actually see Explaining Microscopes http://www.youtube.com/watch?v=ILZEOnQ_glY

8. THE REFRACTING TELESCOPE Same principal as compound microscope, difference being that the object is much farther away Object in a refracting telescope is so far beyond 2F’ that incident rays passing through the objective lens are considered to be parallel Produces two enlarged, inverted images: one real image (located in tube of telescope so it cannot be seen) and one virtual image (image you do see) How Refracting Telescopes Work http://www.youtube.com/watch?v=VzSjqNE2AHM

9. IN SUMMARY A camera uses a converging lens to produce a smaller, inverted, real image of a large object; the object is beyond 2F’, and the real image is located between F & 2F in the camera body A movie projector uses a converging lens to produce a larger, inverted, real image of a small object; the object (film strip) lies between F’ and 2F’, and the image is located beyond 2F

10. IN SUMMARY A magnifying glass, or simple microscope, is a converging lens in which the object is located between the lens and F’. A larger, upright, virtual image is formed on the same side of the lens as the object A compound microscope consists of two converging lenses and produces a larger, inverted, virtual image. The object is located close to the objective lens A refracting telescope consists of two converging lenses and produces a larger, inverted, virtual image. The object is so far away from the objective lens that the incident rays that pass through the lens are essentially parallel