try_get_fnumber

Description:

[ Version ( since = "0.14.0" ) ]
public double try_get_fnumber () throws Error

See <ulink url="https://en.

wikipedia.org/wiki/F-number"></ulink> for more information. If Exif.Photo.FNumber does not exist, it will fall back to calculating the FNumber from Exif.Photo.ApertureValue (if available);

Parameters:

this	An instance of Metadata

Returns:

The exposure Fnumber as a gdouble, or -1.0 if tag is not present or invalid.