 
Sometimes in dark situations you just don’t have enough light to record what’s in front of you, forcing you to ADD light into the scene. This is when flash comes into play in order to properly illuminate your subject. The problem is, the built-in flashes on our cameras are tiny, harsh light sources that wash out and flatten subjects in an unattractive way. While you are able to adjust the power of your built-in flash, getting full control over your additional light source is something you only get with an external flash.
BENEFITS OF AN EXTERNAL FLASH:
– The light is directional: Unlike a built-in flash that can only point directly forward, an external flash pivots and can aim its light in different directions. This means you can use BOUNCE flash, a technique that will soften the light that falls onto your subject because it bounces off of a surface instead of shining directly onto your subject’s face.
– It’s a bigger light source: The main problem with a built-in flash is that it’s a tiny light source. External flashes are obviously bigger in size but can also be modified to be softer as well. Flash domes, diffusers or bounce cards all help to soften the light coming from an external flash.
– It has 3 different modes for more accurate control over the power output: An external flash has three different options for the output it produces. In M (Manual) mode you have full control over the intensity of your flash by setting the power output manually. In TTL (Through The Lens) mode, your flash reads the scene by sending out a flash or signal and automatically sets the power output based on the distance between the camera and the objects in front of it. In TTL mode, your flash knows your exposure settings. In A (Auto) mode, the flash uses it’s built in sensor to do the same thing as TTL but you have to program in some of your exposure information to get an accurate reading.
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