Almost all digital cameras and smartphones save photos with EXIF (Exchangeable Image File) data. Camera settings and scene information are recorded by the camera into the image file. Examples of stored information are shutter speed, date and time a photo was taken, focal length, exposure compensation, metering pattern and if a flash was used.
Cameras with built-in GPS receivers, if enabled, also store precise geographical information (street address, city, state, country) and GPS coordinates in each photo, known as geotags. Embedded geotags raise important security and safety concerns. For more information, read Geotags Compromise Your Security and Privacy
Many camera owners study EXIF to compare successful photos to those that are not. Data provides insight about how camera settings affect photo characteristics such as exposure, depth-of-field and subject movement.
Viewing EXIF data
EXIF data can be read by several applications. The software that came with your digital camera lets you view the data. Other viewing applications include EXIF web browser plug-ins, photo editing and organizing programs and smartphone apps and some printer drivers. The printer drivers use the EXIF data to automatically enhance images and can result in a better looking prints.
Preserving EXIF data
You can keep EXIF information in edited versions of original image files if they are Saved correctly. Most or all of the data embedded in the original will be in the edited file. Check the Help files of your photo editing software for specifics about preserving EXIF information during the editing process.
Viewing EXIF data at photo hosting sites
The information can be viewed online at photo hosting sites. It is often visible under, or to one, side of a photo on display. Or there will be a link or icon near the image that needs to be clicked to reveal the EXIF data.
Different photo hosting sites may use terms other than EXIF. For example, Flickr uses the word properties instead of EXIF; Picasa web albums have an area called Photo information; click on the More Information link to see additional photo EXIF data.
More about browser EXIF viewers
Using a browser EXIF viewer is great if you enjoying viewing photos posted online and want to gain insights about how a photo was taken. See a great action shot? Check the EXIF to see what focal length, shutter-speed and ISO settings were used.
There are EXIF viewers compatible with most browsers that must be installed as a plug-in. Some of the viewers only provide basic data but it can still be very useful.
Once the viewer is installed in your browser, right-click a jpeg image. As shown in the illustration to the left, click the EXIF Data link in the drop down menu. A window will open revealing available data.
For many, reading EXIF data is a worthwhile way to help improve their photo-taking skills.
Related reading: A listing of freeware including EXIF viewers and other useful free programs for the digital darkroom.