1. The "Camera Obscura" effect is latin for "dark room". It is achieved by a small hole created in one wall that acts like a lens, focusing and projecting light onto the wall of the dark room.
2. During the 17th century, Sir Isaac Newton and Christian Huygens finally understood optics and how to make a high quality glass lens. 
3. in 1827 Joseph Nicephore Niepce added film to make the first successful photograph.
4. Modern cameras still have light passing through the lens and into the camera like the olden days.
5. Instead of old plastic film, now digital cameras use digital film ( a sensor called a CCD).
6. The difference between auto mode and program mode is that in program mode you can control the flash, as you cannot in auto.
7. Portrait mode is an attempt to blur out the background by using high f-stop settings.
8. Sports mode is used to freeze fast motions by using the highest shutter speed possible.
9. The half press is important because it auto focuses your subject.
10. The circled arrow means flash is disabled. You would use this outdoors.
11. The arrow with an auto means auto flash. You would use this in a darker setting such as outdoors at night.
12. If there is too much light in a photo, the subject will be washed out.
13. If there isn't enough light, then it will be too dark.
14. A stop is a measurement of light: the more light.
15. it would be 1 times brighter.
16. it would be two times brighter.
17. A longer shutter speed has more light.
18. a shorter shutter speed has less light.
19. Brightness is reduced when light goes through an aperture.
20. A larger aperture opening gives off more light.