Registered: Nov 18, 2002
Total Posts: 9311
Country: United States
The most important factor in making flash lit shots look natural is matching the angle natural light hits faces most of the time — an average 45° downward angle.
Flash in the hot shoe winds up at a lower angle, especially in portrait mode, causing the lighting to create flatter light with fewer shadow clues about 3D shape and highlight clues much lower on the cheeks, chin, etc. that natural light. Hence it looks "fake" — because its too low relative to the face.
Bounce is a solution but you need to watch the angle the light comes off the ceiling. If it gets too steep the brow will shade the eye — look critically at the eyes to make sure they are as bright in the sockets as the cheeks. Getting up above the faces and having the people look up will help get the bounced light into the eyes.
Bouncing is very inefficient because 80% if the light will be illuminating things not in the photo. A better alternative is a bracket and diffuser...
See: http://photo.nova.org/CanonPracticalUsage/
The bracket works by creating that natural downward angle mentioned above. With the bracket changing the it is not necessary to bounce to do it so you can direct all the light forward more efficiently for greater range / shorter recycle times.
The diffuser is useful outdoors where bounce isn't an option, but the diffuser will also cut range. Outdoor if you are on ground level with the subject eye-to-eye their brows will shade the eye sockets as with bounce indoors. The solution is the same. Find something 1-2 feet high to stand on and have them up into the camera. Obviously this works best when the sun is at their backs.
Direct flash will also work OK outdoors if you position in so it is not creating shadows visible by the camera. If you don't have a bracket keeping the flash in landscape mode and above the lens will produce more flattering lighting than portrait mode with it low and off the side of the lens.
Moving a single flash off axis will create better modeling via the shadows it creates but if you also don't have a fill source the shadows will be so dark and unflattering it may trump the better modeling. As shown in the link the better solution as a 580ex class master on the bracket as fill controlling the tone of shadows the off camera slave created. That gives you total control of the two most important elements: pattern and tone (i.e. lighting ratio). For women and kids lighter shadows are more flattering than heavy dark ones.
