Any amateur class digital camera has a small inbuilt flash which has enough power to illuminate the object being shot within a distance of 2 to 4 metres. Higher-class cameras have a special mount which can be used to connect a more powerful or even a professional flash with a range sometimes reaching up to 20 metres or more. Normally, a flash will be used to illuminate the desired object when the ambient light is not enough. This is also the way the automatic settings of your camera work when you shoot in full auto mode. In this mode the flash will automatically turn on if the light is not sufficient.
Using the camera menu or a special functional button with the flash sign, you can select some additional flash modes. One such mode which is used quite often is the ‘red-eye reduction’ mode. It is usually designated with an eye symbol and its function is to reduce the red reflection from human eyes when we shoot. In this mode the flash produces one or several smaller bursts before the main one, whose aim is to contract the pupil of the eye and prevent the appearance of this unpleasant effect. You should keep in mind, though, that when using this mode the person you are shooting should be looking straight into the camera. Also, there is a certain lag when using this type of flash because of the need for flash bursts before shooting.
If the flash is an external one and has a tilting or articulating head, it could be pointed at the ceiling or any of the walls of the room so that you could use the reflected light, which is much softer and has a much more appealing effect on the object being shot, because it does not create any sharp shadows or bright highlights. Another method is to place a special light softener (diffuser) blocking the light from the flash. You can make one yourself from race paper or another similar material. The effect from this device is a softer and more uniform light. In nature clouds play the role of natural light diffusers, which is the reason why in cloudy weather we obtain better portraits without the sharp shadows we tend to have when illuminating the face directly.
Another commonly used operation mode is the so-called ‘Slow motion synchronisation’. In some cameras this method is marked with an ‘S’ (slow) while in others it is marked with a night photography symbol – a moon and a star. It is used when you want the flash to turn on, but you want the shutter speed of the camera to remain adequate to the external light. In this mode you can take interesting night photographs in the city, where the objects in the foreground will be lit by the lighting, while at in the background you can see the natural lights of the urban landscape. In some cameras there is a special option (synchronisation by front or back curtain) where the flash is turned on the moment the shutter is opened or the moment it is closed. This provides you with the opportunity to achieve additional interesting effects for night photography and long shutter speeds.
In this mode you can set the camera at longer speeds and to press the shutter button while drawing circles or any other movement, or play with the length of the zoom lens (if it is an optical zoom lens) while shooting. In this way the light will leave interesting arches and lines, while the object will be still and illuminated with the help form the light from the flash.
Last but not least, it is very important that your camera should support or should have the option for forced flash regardless of light conditions. This is often the case when we shoot outside under unfavourable light. In some camera models you can adjust the power of the flash and increase it later, if that is really necessary, or to decrease it so that it is used as delicately as possible, without it interfering with the magic spell of the natural light. In some cases you cannot tell that a flash has been used.
For the three pictures below we used a small cheap Godox flash with a wireless transmitter in the set. The transmitter is mounted onto the camera, while the flash can change its position based on the object in order to obtain interesting dimensional lighting. Shoot in manual mode ‘M’ in order to have precise balance between the light from the flash and the background.
In conclusion, we can say that the flash is a wonderful assistant in many situations, but if you want truly interesting results, you must be familiar with all of its operating modes and to use them appropriately.
The creative use of external flash and the effects which you can achieve with it will be described in detail as an additional topic.