1. Pinhole Cameras Converging & Diverging Lenses

2. Pinhole Image

3. Pinhole Camera Image is upside down and left to right reversed Size of image is determined by distance from pinhole to screen/film The smaller the pinhole, the clearer the image & the dimmer the image

4. Pinhole Camera Picture

6. Pinhole Viewing of Partial Eclipse

7. Shape of a Lens

8. Types of Lenses

9. Convex Lens Terms

10. Three Rays to Locate Image Ray parallel to axis bends through the focus. Ray through the focus bends parallel to axis. Ray through center of lens passes straight through.

11. Characterizing the Image Images are characterized in the following way – Virtual or Real – Upright or Inverted – Reduced, Enlarged, Same Size

12. Object Beyond 2f Image is – Real – Inverted – Reduced

13. Object at 2f Image is – Real – Inverted – Same size

14. Object Between 2f and f Image is – Real – Inverted – Enlarged

15. Object at F No Image is Formed!

16. Object Closer than F Image is – Virtual – Upright – Enlarged

17. Converging Lens Images

18. Eye Optics Accommodation – Shockwave Applet

19. Normal Eye In the normal eye, the cornea/lens system project an inverted, “focused” image on the retina – which is the screen.

20. Myopia -- Nearsightedness In a nearsighted eye, the image is “focused” in front of the retina. A diverging (concave) lens is used to cause the image to be “focused” at the retina.

21. Hyperopia -- Farsightedness In a farsighted eye, the image is “focused” behind the retina. A converging (convex) lens is used to cause the image to be “focused” at the retina.

22. Astigmatism In astigmatism, the cornea is irregularly shaped & the light focuses at multiple points. The result is blurry or multiple images.

23. Concave Lens Ray Tracing Ray parallel to axis refracts as if it comes from the first focus. Ray which lines up with second focus refracts parallel to axis. Ray through center of lens doesn’t bend.

24. Image Formed by Concave Lens Image is always – Virtual – Upright – Reduced

25. Concave Lens Image Distance As object distance decreases – Image distance decreases – Image size increases

26. Image Characteristics CONVEX LENS – IMAGE DEPENDS ON OBJECT POSITION – Beyond F: Real; Inverted; Enlarged, Reduced, or Same Size – Closer than F: Virtual, Upright, Enlarged – At F: NO IMAGE CONCAVE LENS – IMAGE ALWAYS SAME – Virtual – Upright – Reduced