One of the cool things about this little camera is the built-in flash- called a "Speedlight" by Nikon. Neither the Nikon F100 or F5 have the built-in Speedlight. This little flash unit is tucked into the body until needed.
Simply push the little button on the side of the prism finder, and the flash pops up, fully charged and ready to go. The flash has a guide number of 39 with ISO 100 film, which means it will cover your subjects well out to 10-12 feet or so. It is not as powerful as an external flash unit, but it is always with the camera. You can always pop it up for a snapshot or fill flash.
There is also a "hot-shoe" on top, so that you can use a more powerful external flash unit for greater distances. The built-in flash has a beam width that will cover the view of a 28mm wide-angle lens, and any longer lens. A new technology that Nikon includes in this camera is "3D Multi-sensor Balanced fill flash." This is a technical name for a new technology that helps your flash pictures come out very well, even in bad photography conditions.
As an example, you have probably seen flash pictures where the subject is "burned-out" or faded due to too much light. This is because the camera is trying to average out the flash coverage in the picture. With most other cameras, if there is a dark background then the subject will usually be burned out. The N80 will rarely give you a picture with burned out subjects. What makes it different is how it looks at the scene to be lit by the flash. When you press the shutter release button a rapid series of events occur. First, the mirror inside the camera moves up out of the way. Then the N80 fires five quick flashes (called monitor pre-flashes) that allow the camera to examine the potential picture area. As each of the pre-flashes occur the camera meter looks at a different section of the scene. If one or more sections reflect almost no light, or too much light, they are ignored. Then the shutter opens and the main flash fires, fully exposing the scene, but balanced for the subject. After that the mirror returns to its down position. It is impossible for most people to see the five pre-flashes, since all this is happening so quickly. To the user and subject it just looks like a single burst of light from the flash.
If a "D" or "G" lens is used, this system is even more accurate since it can more easily determine exactly where the subject is in the photograph. Also, if a more powerful external flash unit is used, such as the Nikon SB-50, and SB-28, the five monitor pre-flashes are fired by the external unit, just like the built-in flash unit.
The built-in flash unit uses this same technology to provide very accurate "fill" flash. As an example, let's say that you are taking a picture of some friends standing in directly overhead sunlight. Their noses and chins will cast long weird looking shadows. Or, if a hat is worn, the brim blocks the light so much that the face can disappear. If you pop open your N80's little flash unit, it will sense that there is a lot of available light, and will attempt to let that light provide the main exposure. It will only provide "fill" flash that tends to remove the weird shadows, and provides "pop" to the image. It does this without making the image appear unnatural or unbalanced. In most cases, an average person will not be able to tell that fill flash was used. The photographs just look really good, since there are no heavy shadows, or overexposure of the subject. The light from the flash is "balanced" with the light from the surroundings.
This new "3D Multi-sensor Balanced fill flash" with "5-segment TTL flash sensors" is a very powerful technology, and gives Nikon users a distinctly better flash system. It can provide Slow Sync, Rear Sync, Red-Eye Reduction, and Flash Compensation from +1 to 3 EV in ½ steps.