EXIF data from a digital photograph is displayed in Adobe Photoshop. While most traditional cameras store a very limited amount of information inside photographs, some new cameras, and many camera-enabled cell phones store precise GPS coordinates of where each photo was taken.
As new generation of digital cameras take to the streets, photographers who share their digital photos are now contending with issues of privacy, and may be inadvertently sharing more than just visual imagery.
Recently concerns have surfaced as a number of popular online photo galleries and social networks have begun extracting personal information from photos and sharing it with the public. In many cases it's information that the amateur photographer didn't even know even existed.
Digital cameras have actually been storing additional bits of information inside photographs - details like the camera's shutter speed, aperture, ISO speed, the date and time - for many years now. This extra information, referred to as "EXIF" data by camera manufacturers, provides the professional photographer with technical details that can help them replicate past successes and avoid future failures. It helps them know which camera settings will give them the best results.
But a new breed of GPS-equipped cameras now have the capability of storing GPS coordinates - latitude and longitude - inside the photo as well. These bits of information indicate precisely where in the world a photo was taken. And while it can be personally useful to a photographer, it may not be information that he or she wants others to have.
For example, a photo of an obscure historic site could reveal its actual location to thousands of people who might choose to damage the site. Or photos taken inside a private residence might tell others where the home is located. There are dozens of scenarios in which this extra information could cause unintended privacy woes.
Relatively few mainstream cameras on the market at this point actually contain the necessary GPS hardware to store GPS information, particularly digital SLRs. But new camera-equipped cell phones are a different matter all together.
Higher-end, multi-function devices dubbed "smart phones" are often GPS equipped and typically camera ready. Most are well integrated with popular online photo galleries and social networking sites. And in most cases, these phones accompany their owner everywhere they go, making it even easier for them to unintentionally divulge their location.
For photographers who must share work with online providers who openly share EXIF data to the public, there are a number of programs, some commercial and some free, that can delete EXIF data before it is shared or uploaded. IrfanView for Windows (free for non-commercial use), which is primarily an image viewer, can scrub all EXIF data. JHead, a command line utility, can also strip photos of this extra information.
For more information, search online for "EXIF".