When to use the flash
The main purpose of the flash is to fill in light. If you are taking photographs in bright sunlight, it’s better to take people into the shade to photograph them and use the flash as it will fill in any shadows in a photo. If a person is not looking towards the light – if they have the sun behind them, or if they are wearing a hat – their face will be in the shade so using the flash will enhance the face but it’ not strong enough to be too bright.
When shooting in automatic mode, the flash will automatically pop up as the camera is trying to help you take a photo with adequate light. It will also raise the ISO to give you additional lighting. As this is not necessarily what you want, it’s better to shoot in manual when using the flash so that you can control all aspects of the shot.
Built in flash – The camera’s built in flash is small and not very powerful and you are unable to modify the direction of the flash
If you are taking photographs in bright sun, it’s better to take people into the shade to photograph them and use the flash
TTL – stands for ‘Through the lens.’ This means that the flash sends out a brief pre-flash to measure the amount of light reflected back off the subject through the lens. This is used to judge the required flash power based on your camera settings.
Sync speed – is the limit of the shutter speed with some flashes. On the Sony A7 and A77ii that I use, the maximum shutter speed is 1/250. On other camera it is lower at 1/200
Flash exposure compensation – this can be adjusted in your settings to change the power of the built in flash. If you’re using an external flash, you can change the settings on the device.
What are the other advantages of using flash outdoors, apart from filling in shadows?
- To freeze the subject – it will be sharper / less blur
- To saturate colours
Some examples of photos with and without the flash:
The following three examples show how the photograph changes as you increase the brightness of the flash:
There isn’t really a right or wrong result. It depends on the effect that you are trying to achieve, as well as personal taste.
The following pairs of photos are taken both with or without a flash:
The following slideshow demonstrates how using a flash can freeze the action. The top butterfly was fluttering over the lower butterfly. It was moving quite fast and without the flash, there may have been substantial blurring and using a higher shutter speed alone to capture the action would have made the photo too dark.
Unfortunately I forgot to check the ISO before I took this photograph and it was set to 1600. I would have had brighter photos had I checked it and set it lower.