What is the purpose of the add-on flashes for cameras?

Question: What is the purpose of the add-on flashes for cameras!?

http://www!.flickr!.com/photos/joelemke/24!.!.!.

!.!. like the one Sara Kiesling has attatched to the top of her camera in that picture!.

What does it do!? Why is it used, and what is it for!?

Those are like all basically the same question!.!. oh, well!.
:]]Www@QuestionHome@Com

Best Answer - Chosen by Asker:

There are a couple of reasons for using an external add-on flash!.

The first is that some cameras just don't have a built-in flash!. This is especially true of most higher end pro cameras(Canon EOS 1/1D/1Ds, Nikon F6, Nikon D3), and most any SLR made before about 20 years ago!.

The second is more power!. Most even, even the most basic off-camera flash is at least twice as powerful as the built-in pop-up flash, and can be more powerful by a factor of ten even!. For most situations(short of the next point to be made), the additional power isn't necessary per se!. It does play into the fact, though, that usually several shots can be made in sequence without needing to wait 5+ seconds in between to recharge the capacitor!.

Along those same lines, most external flashes are powered by four or more AA batteries, so the capacitor will usually charge faster than with the built-in flash!.

The third, and most important, is that external flashes usually have a flash head which can be tilted up and swiveled around in several different directions!. This allows you to, rather than shining a powerful light directly at the subject(deer in the headlights look), indirectly light the subject by bouncing light off of a wall or ceiling!. This provides a much more natural look!.Www@QuestionHome@Com

Can be used as a fill or main light, more control in direction of light (can be bounced off the ceiling or wall, pointed directly at subject, etc!.), stronger than an on camera flash!.

A good Nikon flash is the Nikon SB-800 ($321!.83 from Amazon)
http://www!.amazon!.com/Nikon-SB-800-Speed!.!.!.Www@QuestionHome@Com

These flashes project light off the ceiling of a room, so it looks as if it is natural lighting, other than the flashes that flash directly at the subject and make things look washed-outWww@QuestionHome@Com