Conditionally disable canonical URLs for pagination

// Disable canonical urls for pagination
add_filter( 'redirect_canonical','custom_disable_redirect_canonical' );
function custom_disable_redirect_canonical( $redirect_url ){
    global $post;
    $ptype = get_post_type( $post );
    if ( $ptype == 'collection' && is_archive() ) $redirect_url = false;
    return $redirect_url;
}