Use the AE Lock
That button on your camera marked AE is the Auto Exposure Lock and it’s really useful when you’re shooting in high contrast conditions or your subject is in different light to its surroundings – it could be backlit, through an archway or maybe in a shaft of light against a dark background for example.
All you need to do is zoom in or walk towards the main subject so that it fills the frame and press the AE lock button to lock the exposure.
Then zoom out or step back to compose the shot and take the image using the original exposure settings.
The AE lock usually locks the exposure for a few seconds, but some cameras offer an option in the menu to lock it until it is actively unlocked.
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