This is part of a series of articles on the basics of flash photography. To start reading this tutorial from the beginning, click here.
Using a speedlight flash is quite simple–despite the way flash manufacturers make them look. In this flash photography crash course, I'm going to show you the four functions that every speedlight has that you need to know. Only four functions. Know these four settings and you'll know enough about your flash to competently use it.
I'll show you these functions on the YN-560 flash that I recommend, but the exact same functions are available on any speedlight flash.
1. Power on/off Yes, this is one of the functions! When I said using a speedlight can be simple, I meant it! The only trick you should know is that most flashes don't instantly turn on when you tap the power button. You usually have to press and hold the power for a couple seconds.
2. Flash power All flashes allow you to set the light output or intensity, which is the power or brightness of the flash.
One thing you'll quickly realize as you set the flash power is that more power = slower recycle time, or the time between flashes that it takes for the flash to get power from the battery. When possible, it is best to use your camera settings to gather more light (higher ISO or lower f-stop) and lower your flash power. Keep in mind, though, that this will affect the ratio of light from the flash to the ambient light.
3. Trigger mode
All flashes allow for at least two triggering methods. The first is manual, which simply means you are using a trigger/receiver setup to tell the flash when to fire. The second option is slave mode.
Slave mode, in this sense, means that the flash should fire only when it sees the pop of light from another nearby flash. This is helpful when you are using multiple flashes and don't have enough receivers for all the flashes. However, slave mode rarely works well outdoors or where there is strong ambient light, and doesn't work well when a flash is tucked behind a lighting modifier that would block the light from the other flash.
As a side-note, you may find that your model of speedlight has more than one slave mode (s1 and s2, for example). These differ on the particular model of flash you use, but generally one of them is programmed to ignore pre-flashes. A pre-flash is the tiny nearly invisible pop of light from a flash before the main pop of light.
4. Flash zoom
The zoom of the flash focuses the lens in front of the flash so that it constricts or widens the beam of light that the flash puts out. When a flash is put in a light modifier, it should always be set for the widest beam possible. This way the flash will take full use of the light modifier and fill all of it with light.
Using your flash is that simple. With four functions you can create any photo you want with flash. Most flashes have more functions than this, but I would encourage you to stick to these for now and only learn the other functions as you need them.