Missing tag for Canon's Distortion Correction

Started by vale, June 04, 2019, 06:04:15 PM

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vale

June 04, 2019, 06:04:15 PM
Newer Canon models (like the Canon EOS 5D Mark IV) allow on-camera "Distortion correction" of barrel/pin-cushion distortion.  However, the exiftool doesn't output any tag that would indicate if the camera had this option enabled/disabled. Does Canon not store this info or does the exiftool simply not output it ?

Phil Harvey

#1
June 04, 2019, 09:19:30 PM
Can you mail me two small JPEG images with all the same settings (manual exposure with the lens cap on)?  philharvey66 at gmail.com

I'll see what I can do to decode this.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Hayo Baan

#2
June 05, 2019, 01:54:16 AM
Phil, I guess you mean one jpg with and one without the distortion correction. The rest of the settings the same
Hayo Baan – Photography
Web: www.hayobaan.nl

Phil Harvey

#3
June 05, 2019, 06:50:48 AM Last Edit: June 05, 2019, 07:15:06 AM by Phil Harvey
@Hayo: Right.

I looked into this a bit more.  It may be difficult to decode this.  It isn't displayed by DPP4, and I have a note in the code that there is a byte related to this, but it obviously isn't a simple 0=Off, 1=On situation.

- Phil

Edit: Also, I found this:

"Distortion Correction. In addition to Chromatic Aberration and Peripheral Illumination Correction, the Canon 5D Mark III offers Distortion Correction, but only as an option during in-camera raw processing. The camera can't correct for distortion "on-the-fly" like it can for chromatic aberration and corner shading."

So you only have to take one picture, then post-process it.
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

#4
June 10, 2019, 02:39:45 PM
I got the samples. 

Well, it was a simple 0=Off, 1=On situation, but there were 3 separate bytes that went from 0 to 1.  And one byte that went from 0 to 100.  I'll make my best guess as to the names for these, but I don't know what the differences are.

ExifTool 11.50 will decode three of these as DistortionCorrection, DistortionCorrectionSetting and DistortionCorrectionValue.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

vale

#5
June 11, 2019, 01:22:46 PM
That's great news.

I've run the new 11.50 release on these samples but I can't find any of the three parameters you mentioned getting outputted.

Phil Harvey

#6
June 12, 2019, 07:14:01 AM
Oh, sorry.  My mistake.  Somehow that patch missed this release.  I must have forgotten to push the update from my other computer.  It will be in version 11.51.

Yes.  I see from the revision history that this patch got missed in 11.50.

If you really need to see this information now, you can use this command:

exiftool -U -Canon_VignettingCorr_0x0003 FILE

0=Distortion correction off, 1=Distortion correction on

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

#7
June 13, 2019, 09:58:25 AM
ExifTool 11.51 is now available.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

vale

#8
June 13, 2019, 12:08:05 PM
Fantastic. Thank you so much.
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