Direct Flash versus bounce flash

It gives much better results when you can use bounce flash. Direct flash causes 2 or 3 problems:

• a large difference between the amount of light in the first plane and the background. This is a consequence of the laws of physics (inverse square law) and there is not much one can do about it.
  If the foreground is one meter away from the flash and the background is two meters away, the background will receive only 1/4 of the light, that is, -2 stops.
• harsh shadows. This is more noticeable when the source of light is small, so it can be improved by light boxes and similars (light boxes are a good idea but not very practical).
• red-eye. The solution for that is to move the flash away from the axle of the lens (a normal flash at medium or small distances already solves this in most cases). A problem with that solution is that the shadows get more noticeable,

If you can bounce (that means, if there is a ceiling or wall appropriate, (white if you are doing colour, some light colour in the case of B&W)), you can solve all these problems:

• the inverse square law applies only when the light comes from a point source (or something small enough to be considered a point source). If the light is being bounced in a big wall this no longer applies. Light coming from an infinite plane would not decrease with distance. Reflecting light from the ceiling is more similar to that case than to a point source.
• shadows mostly disappear for the same reason. BUT, light from the ceiling can create shadows under the eyebrowns. This is the reason why flashs sometimes have a secondary light always pointed to the front and why accessories like the Luminoquests have ways to reflect 20% light to the front and 80% to the ceiling.
• red-eye disappears since there is (almost) no light being sent parallel to the axle of the lens.