Generally people upload MASSIVE images to their site so opening lightbox at full image size can be very very slow. For this reason Total uses the custom functions called wpex_get_lightbox_image and wpex_lightbox_image throughout the theme to return the “large” size image for any image that opens in lightbox and help keep your site fast.
In some cases though, you may want to use a different image size such as medium or full, for this reason I added the filter “wpex_get_lightbox_image_size” so you can easily alter that.
Tweaking he default size is very simple, below is an example function to add to your child theme’s functions.php file, simply replace where it says “full” to the image size you want.[gist id=”50bd87cfa299f8622ee4″]