Flash Photography Basic Concepts

• Every flash photograph is two exposure in one.
• Ambient light exposure and a flash exposure. 
• Fill flash can be used when the subject is back lit or side lit to eliminate silhouettes or shadows. 
• Flash exposure is not affective by shutter speed.
• settings Aperture and ISO will not increase the shutter. 
• Flash illumination is dramatically affected by distance. 
• Your camera measures ambient light and flash illuminations 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 elminated 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.