Over the last 6-months I've taken a half-dozen or so courses on LinkedIn Learning, read a couple of books, and spent countless hours taking photos trying to level up my skills as a very amateur photographer.
For me, the technical side of photography is a lot of fun; so when I'm admiring people's work, I love to look at the technical details behind a photograph. Such as, aperture, ISO, and shutter speed (also known as the exposure triangle) as a beginner, these details are just as interesting as the photo itself.
The standard for saving all kinds of technical details inside a JPG image is called, "Exchangeable Image File Format" -- or EXIF for short. I'll show you how to quickly display some of those details using a WordPress shortcode.
Before I get into how to display the EXIF data, first we need to talk about image compression on the web. It's kind of a big deal and is a billion dollar business.
In an effort to achieve perfect scores on Google PageSpeed, Web developers will often smush out every byte of data from their codebase-- including images. Often a developer will rely on a 3rd party image compression service like Cloudinary, re.Smush.it, or Ewww. Well, what's the first thing those image compression services do? Strip out any EXIF data for an easy win.
TL;DR: If you want to share and display EXIF data, you may need to tell your photo editor and any image smushing services to preserve it.
Make sure your images have EXIF data to begin with.
WordPress plays nice with EXIF, mostly.
When you upload a JPG to WordPress, it will scan and save most available EXIF data as post meta. No plugin or configuration needed!
EXIF data stored as post meta in the WordPress database.
WordPress doesn't save all the data though, it ignores both Location and Lens data. Displaying the EXIF data is a bit more complicated than just clicking "upload" though. Let's move on...
Finding the EXIF data in the database
Because WordPress saves this as post meta, you can use the
get_post_meta() function to grab it, if you know the image ID. One simple way to find the ID is by opening any image in the Media Library, and looking at your web browser's address bar:
The image ID is can be located in the address bar.
Once you have the image ID, you could grab the data:
$data = get_post_meta( '22579', '_wp_attachment_metadata' );
Which would return:
array (  => array ( [width] => 2048 [height] => 1412 [file] => 2020/06/P1150618.jpg [image_meta] => array ( [aperture] => 5.6 [camera] => DMC-G81 [created_timestamp] => 1592060239 [focal_length] => 109 [iso] => 3200 [shutter_speed] => 0.01 ) ) )
Now that you have an array of data, you could use PHP array destructuring to both pluck and set your data variables at the same time:
// Destructure image meta array, and set variables. [ 'aperture' => $aperture, 'camera' => $camera, 'created_timestamp' => $timestamp, 'focal_length' => $focal_length, 'iso' => $iso, 'shutter_speed' => $shutter_speed, ] = $data['image_meta'];
Now that you have the data, you could display it with:
<?php echo esc_html( $camera ); ?>
I built a very simple shortcode to display EXIF data. The code is available on Github and you're free to fork (or contribute) and use however you'd like.
The shortcode is super simple, and displays Timestamp, Camera, Aperture, ISO, Shutter Speed, and Focal Length. Because WordPress doesn't save Location or Lens information, you would have to pass that in yourself using arguments. Here's the basic usage:
[exif id="12345" location="Enterprise, AL" lens="Panasonic Lumix G Vario 45-150mm"]
Which would display this:
EXIF data from one of the images on this website.
Bonus: Browser Extensions
There are a couple of browser extensions which display EXIF data
- Exifr (Github)
EXIF data can be helpful for budding photographers like myself. It's interesting to see what type of gear photographers use, and how they composed their photos using the exposure triangle.
I hope you find the shortcode helpful!