Every photo captured with a digital camera has metadata attached to it. Metadata literally is “data about data.” Digital photo metadata includes information about the image file and camera settings used at the time of capture.
Reviewing your metadata is a great way to learn from your images. What worked, and what didn’t? What aperture did you use to get the perfect depth of field? What shutter speed produced the right amount of blur on moving water? At what ISO does your camera start to get noisy? Questions like these can help you to become a better photographer.
Metadata also can help you organize your image catalog effectively. Adding to your metadata with keywords, names, GPS coordinates and event details can make your photos more easily searchable.
The metadata panel in Apple Aperture 3 displays equipment details and settings, along with fields to add your own data and the ability to “geotag” shots by searching the location through Google Maps. You also can rate images, add a color label and flag them for follow-up.
TYPES OF METADATA
There are two basic types of metadata: additive and descriptive. Descriptive metadata is recorded at the time of image capture and includes information like date and time, and the various camera settings that were used for the exposure. Additive metadata is information that you add yourself. It helps you to locate images through keywords and image tagging, making it simple to find a single shot even among thousands. You also can add copyright and contact information.
Most of the programs used for image management offer the basics of metadata addition, and some of the newer programs can even do it automatically through special processes like facial recognition.
LEARNING FROM METADATA
Descriptive metadata is a powerful tool for revealing what you did right, or possibly wrong, when taking an image. Checking settings like shutter speed, aperture, ISO, focal length and metering can help you experiment with photo techniques.
Take motion blur as an example. Try photographing a moving subject like water at a variety of shutter speeds. When you review your metadata, you easily can see which shutter speed produced the effect you want. Next time you’ll know!
Stepping through different levels of ISO is a great way to learn the capabilities of your camera. By comparing the results’ higher and lower ISO settings, you can determine the ISO equivalent at which your camera begins to produce unacceptable levels of noise—you’ll know just how far you can push ISO when you’re dealing with low levels of light or a lot of depth of field.