Function to retrieve a picture if there is no picture is attached

Test the value before you use it:

<?php
if ( ! $img = get_field('img_actor', get_the_ID() ) )
    $img = 'http://www.example.com/wp-content/uploads/default.jpg';
?>
<img class="film" 
     src="https://wordpress.stackexchange.com/scripts/timthumb.php?src=<?php echo urlencode($img); ?>&h=251&w=175&zc=1"
     alt="<?php the_title_attribute(); ?>"  
     title="<?php the_title_attribute(); ?>"/>

I recommend not to use the same text for title and alt, this is very annoying for screen reader users.

Related Posts:

  1. How to enable custom fields for pages (if not a bad practice)?
  2. Add a Jquery Datepicker to custom field in post edit
  3. Custom per-page sidebar widgets .. possible?
  4. How to add new custom page or post blocks?
  5. Order Posts by Closest Numeric Values
  6. Transients vs CRON +Custom Fields: Caching Data Per Post
  7. How to update serialized data in the user meta data
  8. Unable to save datetime custom meta field using update_post_meta() function
  9. Guest Author – How can I use custom fields to create guest author link?
  10. Create additional short URL with custom field and 301 redirect
  11. enabling custom fields in admin?
  12. get_post_meta fields don’t show up on posts page
  13. Using custom fields in a filter hook
  14. Function to change meta value in database for each post
  15. Using WP Query to search by multiple meta fields
  16. Get aggregate list of all custom fields for entire blog
  17. How to Identify the Source of a Custom Field?
  18. Include woocommerce custom field value in front-end search result
  19. woocommerce product custom field
  20. How to validate custom field on lost password form before the user id field?
  21. MySQL Query that looks for post with Custom Field, then changes Category
  22. two custom fields question
  23. Woocommerce: Custom fields and email shortcodes, ec_custom_field
  24. How to save multiple options from a dropdown in user profile
  25. How to display multiple images in custom field
  26. How to show a gloabl message on a user profile page (in back end)?
  27. Create Pop-Up Box with Custom Field Content Inside the Loop
  28. Display the contents of a custom field of a page on their child
  29. Adding an editable field to template?
  30. Transferring author information from a custom field to a proper author
  31. Read / Watch / Listen times – meta
  32. Login WP – Connect single field to an external api
  33. adding extra wordpress user info from registration form
  34. Custom Meta Box (SELECT) Not Saving
  35. jQuery – Automatic event trigger does not **really** check my form
  36. Display URL in a Custom Field
  37. Linking Custom Fields to Database Records
  38. Turn raw url into clickable links
  39. Advanced Custom Fields functionality without plugin
  40. Get post ids sorted by meta_key
  41. Advanced Custom Fields Plugin – Unable to get URL from post_object
  42. Plot location on Google map using full address specified in custom field
  43. Display custom field value as a hyperlink
  44. Unable to get specific value from post meta
  45. pre_get_posts : only get posts by wp_usermeta value
  46. Display list of terms having the same custom field value
  47. How to display custom field in woocommerce email orders? [closed]
  48. Custom meta is not being saved
  49. Displaying Custom Field Array
  50. Query post by date (stored custom field meta as yyyymmdd) and differentiate across 12 months
  51. IF Custom field value equals ZERO
  52. Custom Field Repeating When Using foreach
  53. Accessing Custom Fields on Pages
  54. Can I save post meta programatically without setting metaboxes?
  55. How to add a css class to custom field value?
  56. Show custom field on attachment page?
  57. Help setting up a sql query
  58. Advanced Custom fields not available yet during publish_page action
  59. Meta box values are displayed on Custom Fields list. Is it possible to hide them?
  60. Sort posts by custom field value
  61. Help with this custom field conditional if no field is set display nothing
  62. if statement display content even though no data
  63. How to pass custom field value to shortcode?
  64. custom comment_form fields not displaying
  65. Get custom post fields from multiple metaboxes
  66. Get author total post votes from post meta
  67. use custom field value as post category in loop
  68. Searching with Multiple (Parallel) Criteria on Custom Fields?
  69. Save custom field types with this function…?
  70. Compare ACF date field (if exists) and post date and order DESC
  71. How to display custom fields in hestia theme
  72. How to update only certain custom fields in a the cache of a page?
  73. pass custom value from single.php to another file via get
  74. variable not passed correctly to database using custom field
  75. WordPress Blocks, setAttributes not saving
  76. non-unique #_ajax_nonce id in browser console
  77. How do i call up default post title in custom posts
  78. Query to sort a list by meta key first (if it exists), and show remaining posts without meta key ordered by title
  79. Trying to get custom field data in a simple plugin
  80. Sort columns in the ‘Pages’ dashboard overview
  81. Why does this javascript search function in the WordPress Admin not work?
  82. 4 Unique Random Posts based on Custom Field Values
  83. Page template is missing fields or is invalid when I updating the template
  84. create a custom field that let me include other posts
  85. Check if value exists before saving
  86. Get meta value when the page is a blog archive
  87. Add Image With Changeable Link in Custom Field [closed]
  88. Populate a select box with data stored in the database?
  89. Create download page from post option link
  90. Add capability for editors to modify custom fields
  91. How to Pull Out Twitter Summary Data in other areas of my template?
  92. query specific posts according their custom fields, using sql SELECT
  93. Meta_query not filtering posts
  94. Custom fields driven site. I want to make a visual editor driven page template. How?
  95. list pages by custom_field?
  96. Get custom field from page, in a post?
  97. Make Custom Fields Public in JSON – API
  98. Advenced custom fields auto fill problem
  99. Order by a meta field in query loop
  100. Archive for custom fields?