Flash Photography Basics

1. Every flash photograph is two exposures in one
2. Fill flash can be used when subject is backlit or side lit to eliminate silhouettes or shadows
3. Flash exposure is not affected by shutter speed
4. Flash illumination is drastically affected by distance
5. Your camera measures ambient light and flash illumination separately 
6. With automatic flash metering, the flash illumination is measured after the shutter button is pressed, and the flash output is adjusted accordingly
7. Every SLR with a mechanical shutter box has a maximum flash sync shutter speed
8. Harsh lighting, washed out subjects and red eye can be eliminated by using diffusers and light bouncing
9. It is possible to change the order of when the flash fires using  "Rear Curtain Sync"
10. Removing the flash from the top of the camera helps eliminate red eye and unflattering shadows