I looked at the "Focus Distance 2" data of some long shots from the last couple of days.
440m real = 1240m fd2
620m real = 1670m fd2
For very close distance it seems to be ok but beyond 50m or so it really falls apart.
Where does the Focus Distance 2 come from?
Do you have some examples? Are these images from Sony cameras?
One should keep in mind that longer focus distances with short lenses will be wildly inaccurate. In general, camera focus distance measurements are only approximate to begin with.
- Phil
The focus point plug-in (https://github.com/musselwhizzle/Focus-Points) which I have just released as a major update also displays AF relevant tags like focus information.
When implementing this part for Sony, I learned there is no "focus distance" tag by Sony. One reference (https://www.fredmiranda.com/forum/topic/1858744/0) I found said that "Focus Distance 2 is the result of an erroneous user supplied formula to exiftool".
So I was hesitating when a plug-in user requested me to add this tag. I asked him for a thorough review regarding the usefulness of this information. His answer was:
QuoteOk, I did the test.
The same object with four different focus length: 24mm - 105mm - 200mm - 600mm.
The results: 3.6m - 139m - 35m - 30m :-((
You're right, this doesn't any sense.
Which is in line with Phil's statement.