What is EXIF? Understanding Exchangeable Image File Format and Metadata

EXIF stands for Exchangeable Image File Format; a standard arrived at by Japanese industry in 1998. It is metadata (data about the data) appended as a tag to the images you capture with your digital camera. Information such as shutter speed, aperture, focal length, date, time, and even (on certain cameras) latitude and longitude are recorded when a picture is taken. This saves the photographer the pain of taking laborious notes about the “other details” of taking pictures. Its broad adoption makes this information available (and useful) regardless of the model of camera used or its manufacturer.

While having such data at your fingertips is unquestionably useful, there are disadvantages to the standard, as well. Perhaps the most obvious and troublesome is the fact that there is no parent organization that maintains and updates the standard; thus, there are cases where archaic conventions interfere with technological innovations (such as the format’s specified color depth of 24 bits per pixel versus 36 for some new cameras). Another annoying component is the fact that EXIF only supports TIFF and JPEG formats, a very frustrating characteristic if you shoot in RAW format. Even the time feature can be a problem, since there is no time zone information included.

RAW is precisely what its name implies- raw sensor data with no post processing; think of it almost as a digital negative. While you can’t print it or pull it into an image processing program, you can adjust characteristics like white balance, brightness, and contrast before the basic image data has been altered. Further, loss of some of your original image data occurs when saving an image in JPEG format; RAW retains all of this information at the price of being a proprietary format that varies from manufacturer to manufacturer. Some manufacturers even go so far as to encrypt their format to prevent access using 3rd party software.

Click here to learn more about RAW.

Many software programs can access EXIF data. Microsoft Windows XP and Vista, as well as Mac OS X allow access to some of this information when viewing the properties of a file. Software such as ExifTool (available for both Windows and Macintosh computers) can allow you access to the complete metadata for a multitude of file formats. Take advantage of the information- it’s like keeping detailed notes on every photo you shoot without having to keep the notebook!