Extracting Data From Photos

[idontunderstand]

Hi folks many of you may be aware of a feature of digital cameras (and camera phones) called EXIF (Exchangeable Image File Format). This allows information about the picture to be stored in the image itself.

EXIF.org | EXIF and related resources

This can be useful when trying to verify information regarding UFO pictures.

Take this picture for an example -:

F-16 fighter pilot Col. Brian Fields, now retired at 61, was at his Van Buren, Ark., home Jan. 9 when just before 7 p.m., he observed two intensely bright lights as he looked to the southeast close to the horizon

If we use a freeware program called EXIF reader we can see the EXIF data stored in the picture.

Exif Reader - English Version

You can see from the screen shot that the time information that the photographer gave, and the digital time do not match exactly. Now it could be the case that the digital time is set incorrectly, or the photographer mistook the time of the event etc. But at least you have something to work with.

Perhaps more useful is if you have a series of photos where an object is moving. Take the example below of picture A and B.

Picture A : Taken 19:20:30
Picture B : Taken 19:20:42

Regardless of the exact clock time, you have a time duration between the first picture and the second. This would be reflected in the EXIF data.

You can calculate the speed of the object using the data from EXIF, and the distance measurement of the object in the photo.

Speed = distance / time

Just an interesting use of data that comes from modern digital cameras.

Cheers!

 

[CapnG]

My knowledge of trigonometry is shaky at best.. okay be honest, practically non-existant (high school was such a very long time ago...) but it seems to me that if you don't know the distance of the object from the camera lens or the size of the object itself, trying to calculate the speed is somewhat pointless, since it will be entirely dependant on that information.

What do I mean? Well, say you had a small object near the camera and took two pictures of it after moving it say, a foot to the left. Now, say you had a large object away from the camera and you took two pictures of it but moved it say 20 feet to the left. In terms of scale, both objects are the same size in both sets of photos and occupy roughly the same positions but obviously the large object has to be much much further away from the camera than the small object (otherwise it wouldn't be the same size in the photo).

 

[idontunderstand]

Yeah I agree, its only really useful for objects that you can determine are moving in a relatively straight line (in relation to the observer), and you can be fairly certain of your distance away from the object.

It helps if you have objects behind the object, mountains etc as reference points. And landmarks in front of it, then you can have a guess at its distance.

Not perfect of course, but in a world of speculation about UFO's I'm doing my best lol

Cheers!

edit -: Also forgot to add, the focus of the object in relation to surrounding details, buildings, hills, telegraph poles etc, can give a clue to its distance. This is where the EXIF data could help as it has a complete record of the cameras focus, exposure etc.

 

[Aaron LeClair]

I'm seeing the times being the same on the screen shot. What am I missing?

/edit. I am guessing you mean the time he gave 7 pm doesn't match the program. I was looking at what you circled before.

 

[CapnG]

I had a thought about the time differential that would be completely inocuous: Daylight savings.