ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: hbendig on September 18, 2014, 11:10:17 AM

Title: Differences in EXIF data reports
Post by: hbendig on September 18, 2014, 11:10:17 AM
Hello from a Newbie,

I'm using the ExiftoolGUI on Win7, my camera is a Panasonic Lumix FZ1000.

When exporting EXIF data from ExiftoolGUI as text file, there I find parameters like Hyperfocal Distance or Field Of View.
I do not see these data in an exported HTML file, nor in the ExiftoolGUI itself.

Are these regular EXIF data, written by Panasonic?
Why can't I find them in the HTML and in ExiftoolGUI?

Why doesn't a program like PhotoMe show these data?

Any help is appreciated, thank you.
Title: Re: Differences in EXIF data reports
Post by: Phil Harvey on September 18, 2014, 11:14:00 AM
These are Composite tags (https://exiftool.org/TagNames/Composite.html), derived from the values of other tags.

Perhaps there is an option in the GUI to turn on/off the generation of these Composite tags (corresponding to the exiftool -e option)?

- Phil
Title: Re: Differences in EXIF data reports
Post by: hbendig on September 18, 2014, 11:20:54 AM
Gee, now that's what I call fast. Thank you!

Is it listed somewhere how these values are being calculated, or should this be 'common knowledge'?
Title: Re: Differences in EXIF data reports
Post by: Phil Harvey on September 18, 2014, 11:27:43 AM
All of the gruesome details are in the ExifTool source code (freely available), but for your convenience:

HyperfocalDstance = FocalLength^2 / (1000 * Aperture * CircleOfConfusion)

CircleOfConfusion = (sensor diagonal size in mm) / 1440;

The FieldOfView calculation is significantly more complicated, and also depends on FocusDistance to second order.

The code is in the lib/Image/ExifTool.Exif.pm (https://sourceforge.net/p/exiftool/code/ci/master/tree/lib/Image/ExifTool/Exif.pm) module.

- Phil
Title: Re: Differences in EXIF data reports
Post by: hbendig on September 19, 2014, 01:51:53 AM
Great, many thanks for your help!