When taking a photograph with the digital camera, the camera not only stores the date and time in the image file but also the settings of the camera used . This information is recorded in the Exif metadata of the photographs and can include details on the model of the camera itself, the lens that has been used, the shutter speed, aperture, focal length and so on.
Some modern digital cameras and even those of mobile phones are enabled for GPS location and can therefore also save the geographical position of each photograph with the coordinates (latitude and longitude) to know where it was taken.
All these " metadata " are embedded in the photos using the Exif standard which can be easily read by image viewing programs and photo sharing web applications such as Flickr and Picasa Web Albums.
With the Exif you can understand which camera a beautiful photo was taken with on the internet, where it was taken and when .
There are also those who, looking for images on the internet and comparing Exif metadata, created a tool to find the stolen camera .
To view the Exif data of the images you can use a basic and complete program such as IrfanView, the best program for viewing images on the computer.
In IrfanView, you can press the I button to view the information card on a photo and, if Exif metadata exists, there will be a button to view it in detail.
Alternatively you can use the Exif Viewer online tool, upload the photo to the site (or if it is on the internet simply copy and paste the URL of the image) to see a nice summary of all the meta-data stored in that photograph with the location information.
Alternatively, you can use Google Picasa, Windows Live Photo Gallery or any other photo viewer to view Exif photo data on your computer.
The most curious and innovative website that works with Exif is to find the camera stolen from the serial number.
Basically, you can upload a photo taken with your digital camera (by dragging) on the Stolen Camera Finder website or type the serial number of the camera and start a search on the internet.
If another online photo taken from that same camera is found, the thief can be caught.
Unfortunately, this ploy works rarely, because there are few camera models that store the serial number in Exif data (see list of supported cameras).
There are also some models that store an internal serial number in EXIF tags other than the serial number indicated on the camera itself.
However, what can be done today is to prepare a mechanism for finding one's digital camera .
Meanwhile, try to verify that the camera stores the serial number in the Exif data and that this corresponds to the real one.
Since this Stolen Camera Finder cannot have information on all the cameras in the world, you can instruct it by uploading some photos on the internet and see if the search finds something about the serial number of your camera.
If not, you can add the serial number to the database by contacting the administrators so, if one day this camera was stolen, you will still have hopes of finding it .
On the site, on the help page there is also a specific web application called Flickr Scraper to search for photos on the popular photo sharing site.
To try to find out if someone has stolen their own photos on the internet, you can try searching for similar images and similar photos with some web applications like TinyEye.
Returning to Exif metadata, I conclude the discussion by citing the article on the best programs to edit or delete EXIF on photos .
