We'll create fresh WordPress site with wp-extraexif installed. You have 20 minutes to test the plugin after that site we'll be deleted.
The plugin expands the image meta by extracting data via exiftool. The default set of keywords is:
-MIMEType', '-FileType', '-FileName', '-ModifyDate', '-CreateDate', '-DateTimeOriginal', '-ImageHeight', '-ImageWidth', '-Aperture', '-FOV', '-ISO', '-FocalLength', '-FNumber', '-FocalLengthIn35mmFormat', '-ExposureTime', '-Copyright', '-Artist', '-Model', '-GPSLongitude#', '-GPSLatitude#', '-LensID'
which can be altered with the wp_extraexif_exiftool_vars
filter (one argument, an array with the values above).
Later on the extraced values live in the same place where the default, WordPress extraced EXIF lives and can be access from the same array.