Custom Fields Wordpress loop

CustomFieldWP.php

                $args = array('post_type' => 'post_alcalde', 'posts_per_page' => 10, 'order' => 'ASC');
                $loop = new WP_Query($args);
                $slide = '';
                while ($loop->have_posts()) : $loop->the_post();

                    $imagenfull = get_field('imagenalcalde');
                    $imagen = $imagenfull['url'];

                    ?>

                    <div class="foto-alcalde">
                        <img src="<?php echo $imagen ?>">
                    </div>

                    <?php
                endwhile;