Display multiple users from multiple roles

Hi all,

I have a couple of custom user roles on the site I’m currently creating. I’d like to output the users of all these custom roles onto a page with their name and user role displayed. I’ve amended some code (found here Matt Varone) which allows me to output these details for one custom user type

// prepare arguments
$args  = array(
// search only for Authors role
'role' => 'photographer',
// order results by display_name
'orderby' => 'display_name',
);
// Create the WP_User_Query object
$wp_user_query = new WP_User_Query($args);
// Get the results
$authors = $wp_user_query->get_results();
// Check for results
if (!empty($authors))
{
    echo '<ul>';
    // loop trough each author
    foreach ($authors as $author)
    {
        // get all the user's data
        $author_info = get_userdata($author->ID);
        echo '<li>'.$author_info->first_name.' '.$author_info->last_name.'</li>';
    }
    echo '</ul>';
} else {
    echo 'No authors found';
}

What I’ve been unable to do is do this for multiple user roles as the role will only accept the one string.