Flash Photography Basics

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