Friday, 27 April 2012

EXIF FILES





Recently it has been brought to my attention that the term "EXIF File" is being thrown around by paranormal teams and investigators, without any real explanation of what it is, what it does, and how it is used. I thought I would take it upon myself to explain for you, Constant Reader, what an EXIF file is, and what it does.
EXIF data can also be found in other photo file formats, these are "RAW" (associated with DSLR) and "TIFF" formats, we may discuss these at a later point.
 The reason behind its prolific use of late has to do with accusations from some sectors of the paranormal community in regards to teams "Faking" photographs of ghosts.
EXIF Files are very useful in finding out certain information from when the photo was taken, and if it has been tampered with electronically, this is not by any means infallible information, as you will see as we get further into this research and discussion.


- Allen Tiller
What does EXIF mean?

 The Acronym "EXIF" stands for   "Exchangeable Image File Format"

So What is it?

EXIF is a non-industry approved standard that was created by the "Japanese Electronic Industries Development Association" to capture data associated with tagging aspects of Smart Phones, Digital Cameras, Scanners, and Audio associated with these media types. It can also capture Geo-location data via satellite in certain smart phones and newer camera.
Stored information can include, but is not limited too,  shutter speeds, date and time a photo was taken, focal length, exposure compensation, metering pattern and if a flash was use, this is what is known as a "metatag"

So who uses it?

 Professional Photographers often examine their EXIF data to compare two or three photos taken in succession, as one photo may be considered "successful" where as two others may not. This gives the photographer visual clues as to what may have went wrong with the "unsuccessful" photo's, allowing one to adjust or compensate in future photographic shoots.
 Paranormal Investigators are often flooded with photos from the public asking "what it in this photo?", a vast majority of the public are honestly unaware of what an image could be, but there is that small percentage that fake a photo to try and catch an investigator out . This is where EXIF data can be utilised by the investigator to determine if tampering or photo-shopping has been done to the photo, it can also expose the current trend of  phone APPs that create ghost images - however, as I said in my opening paragraph, it is not infallible.

So how do I see it?

 To view your EXIF file data you have a few options, the software that came with your digital camera should allow you to view the data. You can also find EXIF web browser plug-ins online, photo editing and organizing programs usually have an option for viewing as well.
 You will find in different programs different terminology used other than EXIF, in Picasa the term "Photo Information" is used, where-as in Flikr it is referenced as "Properties"

Most Internet Browsers have plug-ins availbale that will allow you to view the EXIF data of photo's posted online. This is useful if you are interested in examining different aspects of photography, or want to improve your own technique.

This link will take you to a site that shows a variety of different EXIF data from various camera makers
 http://www.exif.org/samples.html

Does it have a drawbacks?

 Yes, here is a brief sample of drawbacks associated with EXIF data sourced from Wikipedia
   - The Exif standard specifically states that color depth is always 24 bits. However, many modern cameras, such as the Nikon D70 which captures 36 bits of color per pixel, can capture significantly more. Since Exif/DCF files cannot represent this color depth, many manufacturers have developed proprietary, non-compatible Raw image formats.

   - Exif is very often used in images created by scanners, but the standard makes no provisions for any scanner-specific information.

  - There is no way to record time-zone information along with the time, thus rendering the stored time ambiguous.

You stated earlier that EXIF files are not infallible, how so?
 I  always check the EXIF file of any photo sent to me, it allows me to see what settings the camera was on, this is valuable information, as often cameras will be set to " night mode" which opens the shutter for a longer period of time. If the camera is focused on a light source, and that light source, or the camera itself moves at any point in the duration of the open shutter, the light will have a streak effect, or a glowing effect. Many people mistake this for ghosts, spirits or other phenomena. 
 I also check to see if a photo has been made on an APP, like the infamous ghost making APPS found on Apple's I-Tunes :
http://itunes.apple.com/au/app/ghost-capture/id349479650?mt=8

The truth is EXIF data can be altered, changed, lost or deleted, and rather easily too, with a variety of programs available to do so. Here are some links with information about changing EXIF data:

http://www.photosurfer.com/fix-enhance/24/how-to-edit-meta-data-or-add-information-meta-tags-to-photos.aspx 

http://www.softpedia.com/get/Multimedia/Graphic/Digital-Photo-Tools/Exif-Date-Changer.shtml

Adobe Lightroom 3:
 http://help.adobe.com/en_US/Lightroom/3.0/Using/WS57264460-DC72-4a1f-A665-1E90907A9FFD.html

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So as you can see EXIF data is not infallible and not really a valid argument when accusing another of faking a photo, because the reality is, you can never be 100% certain the data is, or isn't correct. I normally recommend to all budding paranormal investigators to forget the photography and go with video, as photography gives you an image and no data, no start and finish point, where as video gives you a start point, and action point and an end point, allowing for better examination of a phenomena represented by the images - but, video is also fraught with so many possibilities for tampering, editing and faking....but we'll leave that for a later discussion!


Researched & Written by
Allen Tiller

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