ExifTool Forum

ExifTool => Bug Reports / Feature Requests => Topic started by: HenryvN on April 20, 2018, 10:08:22 AM

Title: Incorrect calculation of ShutterSpeedValue?
Post by: HenryvN on April 20, 2018, 10:08:22 AM
I have the feeling that the ShutterSpeedValue (0x9201) is reporting the value of the ExposureTime (0x829A)
Regards, Henry
Title: Re: Incorrect calculation of ShutterSpeedValue?
Post by: Phil Harvey on April 20, 2018, 10:29:33 AM
Hi Henry,

ExifTool converts both ShutterSpeedValue and ApertureValue to the same units as ExposureTime and FNumber respectively to facilitate easy copying between these tags.  See the EXIF tags documentation (https://exiftool.org/TagNames/EXIF.html) for details.

- Phil
Title: Re: Incorrect calculation of ShutterSpeedValue?
Post by: HenryvN on April 25, 2018, 03:08:50 AM
Hi Phil,

I have attached two text files that were reported on the same JPG file. The only difference is that in the second file the verbose option is on. The syntax:
1: -- %EXIFTool% -a -u -g1 %filename% > c:\temp\exiftooloutput.txt
2: -- %EXIFTool% -a -u -g1 -v %filename% > c:\temp\exiftoolverboseoutput.txt
If you look in the first file, a value of 1/40 is reported for both Exposure Time and for Shutter Speed Value
In the second file, a value of 1/40 is reported for Exposure Time, but 5.322274882 (1123/211) for Shutter Speed Value. This is the correct value.

Best regards,
Henry


Title: Re: Incorrect calculation of ShutterSpeedValue?
Post by: Phil Harvey on April 25, 2018, 08:14:46 AM
Like I said, the value of 1123/211 is converted by ExifTool to seconds for your convenience.

- Phil