debug help for commenter http://www.lehelmatyus.com/659/drupal-8-views-field-templates-naming-convention#comment-857

theme.php

<?php 

function logichub_preprocess_views_view_field(array &$variables){
  $id = $variables['field']->realField;

  if ($id == 'field_blog_authors_target_id') {// || $id==’field_image_target_id’

      $terms = $variables['field']->getValue($variables['row']);
      $tids = array();

      foreach($terms as $t){
        $tids[] = intval($t);
      }

      //log_status('tid' ''json_encode($tids));
      $terms = \Drupal\taxonomy\Entity\Term::loadMultiple($tids);
      $output = ”;

      foreach ($terms as $term) {
        $author_img_url = $term->field_author_image[0]->entity->uri->value;
        $output .= '';
      }

    $variables['output'] = $output;

  }

}