You are photographing a moving subject that briefly passes through a heavily backlit area. To ensure consistent exposure and focus on the subject despite the changing background, which native camera app feature should be used before reframing?

The native camera app feature that should be used is AE/AF Lock. AE/AF Lock stands for Automatic Exposure and Automatic Focus Lock. This combined function is designed to fix both the exposure settings and the focus distance based on the initial point of measurement, preventing them from automatically changing as the camera is moved or the scene shifts.

When activated, Automatic Exposure (AE) Lock samples the light from the specific area you target – in this case, your moving subject – and then holds those measured exposure values, such as shutter speed, aperture, and ISO. This ensures that even as the subject moves into a heavily backlit area, which would typically cause the camera to underexpose the subject by metering the bright background, the subject remains correctly exposed according to the initial reading.

Simultaneously, Automatic Focus (AF) Lock fixes the focus distance on your subject. This prevents the camera from continuously trying to refocus on the changing background, which could be visually distracting or have strong contrast due to backlighting. By locking the focus, your subject remains sharp throughout its movement, even if other elements in the frame change distance or prominence.

To effectively use this in the described scenario, you would first aim the camera directly at your subject when it is in suitable light, or before it enters the backlit area. You then engage the AE/AF Lock feature, typically by pressing and holding on the subject on a touchscreen or using a dedicated physical button. Once locked, you are free to recompose your shot – to 'reframe' – knowing that both the exposure and the focus will remain consistently set for your subject, ensuring clarity and proper brightness despite the challenging and varying background.