Copyright Michael Karbo, Denmark, Europe.
Chapter 25. EXIF data
We have seen than there are hundreds of ways to set a camera. If you don’t use a notebook or a dictaphone, then it can be difficult to remember, which settings you have used for a particular image. But luckily the camera can help us to remember the settings. Every time you take an image, information about how the exposure was taken has been saved. This information is called EXIF data (Exchangeable Image File Format), and can be very useful when processing the images in a computer.
An image report
EXIF data consists ideally of a complete report of how a certain image has been taken. This data can be read in most image programs. This means that you can read all the details about an image’s exposure in a computer. It can be difficult, for example, to remember when you used exposure compensation. Then you can get the image browser to show the image file’s EXIF data.
Likewise, it is often relevant to see how much zoom has been used for an exposure; you can get this from the focal length value.
Figur 100. Some of the EXIF information.
Reading EXIF data
EXIF data is automatically stored in the JPEG files, so the data is always available – it is just a question of reading it. You can use special programs, which are exclusively designed for managing EXIF data. The Japanese Exif Reader is one of them and you can fetch it free of charge on the net. But otherwise EXIF data is easily read in most image programs. Sometimes, unfortunately, the full set of EXIF data can only be read with the software, which has accompanied the camera. But in general there is no need to install special software for this.
Figur 101. When you have taken an image you are really happy with, it can be useful to study the settings the camera had when the exposure was taken.
EXIF data is of great help to the photographer, and it is a system, which is still being developed (and hopefully further standardised). It is expected that future cameras will be equipped with a little sender, which is in contact with a geographical search system. This will mean that the image’s EXIF data will include an address of where the image has been taken. The name of street probably won’t be a part of EXIF data, but it can probably be disclosed by clicking on the EXIF address!
Figur 102. Thumber is another program, which is free of charge and it can be used to copy EXIFdata from one image file to another. If you process an image in a program such as Photoshop Elements, most of the EXIF data disappears so it is always a good idea to save the original file. With Thumber you can, however, re-establish the EXIF data in a new version of the image.