We have got certain image style url in field--image.tpl.php template for implement fancybox gallery. We need link to different size image as a wrapper for this image thumbnail.
Example:
<a href="style/large/image.jpg"><image src="style/thumb/image.jpg" /></a>
Solution (put to field--image.tpl.php "foreach ($items AS $item)" loop):
$item['#path']['path'] = file_create_url(image_style_path('large', $item['#item']['uri']));