acf gallery

1<?php 
2$images = get_field('gallery');
3
4if( $images ): ?>
5    <ul>
6        <?php foreach( $images as $image ): ?>
7            <li>
8                <a href="<?php echo $image['url']; ?>">
9                     <img src="<?php echo $image['sizes']['thumbnail']; ?>" alt="<?php echo $image['alt']; ?>" />
10                </a>
11                <p><?php echo $image['caption']; ?></p>
12            </li>
13        <?php endforeach; ?>
14    </ul>
15<?php endif; ?>

1<?php 
2$images = get_field('gallery');
3$size = 'full'; // (thumbnail, medium, large, full or custom size)
4if( $images ): ?>
5    <ul>
6        <?php foreach( $images as $image_id ): ?>
7            <li>
8                <?php echo wp_get_attachment_image( $image_id, $size ); ?>
9            </li>
10        <?php endforeach; ?>
11    </ul>
12<?php endif; ?>