Change WooCommerce Product Image Zoom Behavior

If you want to change the zoom (magnification) behavior when hovering over a product on the WooCommerce product page, you can use the woocommerce_single_product_zoom_options filter:

add_filter( 'woocommerce_single_product_zoom_options', 'custom_single_product_zoom_options' );
function custom_single_product_zoom_options( $zoom_options ) {
    // Changing the magnification level:
    $zoom_options['magnify'] = 0.7;

    return $zoom_options;
}

Here are the parameters you can change:

$zoom_options = array (
    'url' => false,
    'callback' => false,
    'target' => false,
    'duration' => 120, // Transition in milli seconds (default is 120)
    'on' => 'mouseover', // other options: grab, click, toggle (default is mouseover)
    'touch' => true, // enables a touch fallback
    'onZoomIn' => false,
    'onZoomOut' => false,
    'magnify' => 1, // Zoom magnification: (default is 1  |  float number between 0 and 1)
);

For more WooCommerce product page customization, see Mastering WooCommerce Hooks.