1.When would you use external flash? When your shooting in a dark place

2.Do you need to meter the light if you use flash? No

3.What does flash synchronization mean? When the camera takes a picture the flash flashes

4.What does ETTL mean? Evaluative through the lens

5.What will happen when you shoot faster than the camera sync speed? half of the image will be dark and the other half will be bright

6.Why do photographers bounce the flash and use a diffuser? to soften the light

7.What is a slave? when you take a picture the other flashes go off aswell

8.What should you do if your image comes out too dark or too light? Use a faster shutter speed to decrease the amount of time the sensor is exposed to light.