rewrite the tribe event featured image on single event view templates with a custom size

custom_tribe_event_featured_image.php

<?php

// rewrite the tribe event featured image on single event view templates with a custom size
function custom_tribe_event_featured_image( $featured_image ){
  if( is_single() ){
		$post_id = get_the_ID();
    		$size = 'hbgm-news-full';
		$image_src = wp_get_attachment_image_src( get_post_thumbnail_id( $post_id ), $size );
		$featured_image = '';
		if ( !empty( $image_src ) ) {
			$featured_image = '<a href="'. tribe_get_event_link() .'" title="'. get_the_title( $post_id ) .'" rel="lightbox"><img src="'.  $image_src[0] .'" title="'. get_the_title( $post_id ) .'" class="alignleft" /></a>';
		}
	}
	return $featured_image;
}
add_filter( 'tribe_event_featured_image', 'custom_tribe_event_featured_image');