That worked, in case this helps somebody else:
if ( is_product_category() ) {
// vars
$queried_object = get_queried_object();
$taxonomy = $queried_object->taxonomy;
$term_id = $queried_object->term_id;
$foto = get_field( 'foto', $queried_object );
$foto = get_field( 'foto', $taxonomy . '_' . $term_id );
if( get_field('foto', $taxonomy . '_' . $term_id) ) {
echo '<div class="cat-banner"><img src="' . $foto . '"/></div>';
}
}