What is EXIF data? Aperture, shutter speed and ISO explained

What EXIF means

EXIF stands for Exchangeable Image File Format. It is a block of information that cameras and phones write into a photo file at the moment you press the shutter. It records how the picture was taken, not what it shows.

The fields you will see most

• Camera: the make and model, such as the phone or camera that took the picture.
• Lens: the lens model, when the camera can report it.
• Aperture: how wide the lens opening was, written as an f-number like f/1.8. A smaller number means a wider opening, which lets in more light and gives a shallower depth of field, so the background looks softer.
• Shutter speed: how long the sensor was exposed to light, written like 1/250 s. Faster speeds such as 1/1000 s freeze motion. Slower speeds such as 1/15 s let in more light but can blur movement or show camera shake.
• ISO: how sensitive the sensor was. A higher number such as ISO 3200 gives a brighter picture in low light, but usually adds more noise.
• Focal length: the lens zoom in millimeters, such as 35mm. A smaller number is wider, and a larger number is more zoomed in. Some cameras also store a 35mm equivalent so you can compare across sensor sizes.
• Date: when the photo was taken, according to the camera’s clock.

How to read an example

Take “35mm, f/1.8, 1/250 s, ISO 400”. It was shot with a fairly wide lens, wide open for a soft background, at a shutter speed fast enough to keep a moving person sharp, and at a low ISO, so there was a good amount of light.

Why EXIF data is sometimes missing or wrong

• Screenshots and images made by design tools have no camera, so there is nothing to record.
• Some editing, messaging and social apps remove EXIF data when they compress or upload a picture.
• The date comes from the camera’s clock, so it can be off if the clock was never set or the time zone changed.

When data is missing, you can type the values in yourself in Shutterlune before you export.

Put it on your photo

To print these details under a picture, follow how to add camera settings to a photo.