RE: TOM BRETT'S DESIGNS-UPDATE
We're both kidding, and it's these darn digital cameras that we have all this fuss. EXIF is the format of the data stored in each picture file, and the program (PTLens) looks there for the focal length used for the shot. It has distortion parameters for several cameras/lenses and can undistort pictures automagically.
Save the two T2 pictures to harddisk and view them alternating with the Windows preview program - you'll see the difference.