There are many different ways to alter the light coming out of your pop-up and external flash units and many different reasons you might want to do it.
3 Reasons to alter your flash
- To create catchlights
- To diffuse the harshness of the default burst of light
- To maintain ambiance in the environment where you’re shooting. For example, as soon as you introduce a flash into a lovely party atmosphere, the ambiance gets sucked right out of the room.
Ways to alter & control your flash
1. First and foremost, the most obvious and cheapest (free) way to fiddle with your flash is to turn the strength down. On an external flash, you can dial down the strength if you just need to introduce a little added light and not a full-powered burst. Play with that and see where it takes you.
2. You can bounce your external flash off of nearby ceilings or walls. This will spread the light and change the direction from which it is coming.
3. Lots of photographers do the business card trick to create catchlights in their subject’s eyes and many newer external flashes now come with a catchlight panel attached. But this doesn’t do anything to diffuse or lessen the strength and it doesn’t effect the spread of light. Just know what tricks do what so you can choose what to employ for each different scenario. And incase you don’t know the "business card" trick, it is where you use a rubber band to attach a white business card to the top of your flash unit to create little white reflections (catch lights) in your subject’s eyes.
4. External flashes often have clear(ish) little screens that can pop out of the unit and down over the bulb. This is called a ‘built-in wide panel’ and is used to widen the range of the light coming from the Speedlite. Contrary to popular thought, it is not a diffuser and is meant to be used with super wide angle lenses. This means that the flash won’t just focus on the center of the image.
5. One other method for your pop-up flash is a diffuser which attaches to your hotshoe and wraps around. Some people may find it exciting to construct accessories like these on their own.
6. It’s important that when shooting with a flash in manual mode, you make sure to have the white balance set for flash, especially if you’re shooting JPEG and have limited control on the temperature after the photo has been taken. A flash gives a cool color temperature so setting your WB to ‘flash’ will add a bit of warmth to your scene. If you’re shooting in auto, this will take care of itself but if not, don’t forget to check your settings before you start shooting.
There’s an abundance of further ways to get the results explained above so please share your own tips and tricks below.