1. Telescopes

2. Simple Prism FBends light FSeparates colors

3. Prism  Lens Focal Point Focal Length

4. Keplerian Refractor Objective Lens Eyepiece Lens

5. Typical small Refractor

6. Purpose of a Telescope FGather light PSee fainter objects PProportional to the collecting area FMagnify PGreater detail PM = focal length objective/focal length eyepiece FResolve PSee objects close together

7. Light Gathering

8. 10.7 cm camera 15.2 cm camera

9. Resolution

10. Light Pollution

11. Problems with the Simple Refractor white Chromatic Aberration Spherical Aberration

12. Examples of Chromatic Aberration

13. Example of Spherical Aberration

14. Hevelius and his long telescope

15. Achromatic Doublet Positive, crown glass Negative, flint glass

16. 40-inch Yerkes Refractor

17. Problems of Large Refractors FSupport PCan only support lens by the edge FAbsorption of starlight FImperfections in the glass FGlass flows

18. Reflectors

19. Advantages of Reflectors FNo chromatic aberration FNo spherical aberration FMirrors don’t have support problems FNo problems with imperfections in the mirror or absorption in the mirror

20. Problems of Reflectors FEarly mirrors were metal PTarnished easily PNot very reflective FSome light must be blocked PUsually a second mirror is inserted to divert light

21. Types of Reflectors Newtonian Prime Focus Cassegrain Coudé

22. Earl of Rosse’s Leviathan

23. Mauna Kea

24. Keck Telescopes – 10 m

25. Large Binocular Telescope 8.4 m each

26. Very Large Telescope Four – 8 m

27. Giant Megellan Telescope 24.5 m

28. The OWL Telescope (OverWhelming Large) – 100 m

30. Hubble Space Telescope

31. James Webb Telescope

32. The SFA Observatory

33. Cassegrain Telescopes

34. 10-inch Schmidt- Cassegrain

35. 8-inch Schmidt- Cassegrain

36. CCD Camera and Color Filters