Bug with NikonCustom Tags for Nikon Z6

[fluffycat]

Hi.

I am not sure if this is a bug, or an issue with the metadata written by the camera to the files, but I thought I might put it out here for investigation.

On my Nikon Z6 with a Z 50mm f/1.8S lens attached, running camera firmware 3.60, the following fields are showing wrong information:

ManualFocusRingInAFMode: this option is not selectable in-camera, but the value reflected is based on the setting of a previous lens that can toggle this on/off in the camera
Func2Button: my current setting is set to "My Menu Top Item", but Exiftool shows the value "Zoom (1:1)"
LensControlRing: Exiftool shows the value "None (Disabled)" no matter what settings I put in the camera

While I am not sure why Func2Button is reporting wrong information, but with regards to the focus ring information I have a brief idea of what may be going on.

From my personal experience, the camera seem to have two sets of settings for control rings:
Set A is for lenses with only 1 control ring (like my 50mm f/1.8S)
Set B is for lenses with 1 control ring and 1 dedicated focus ring (like the Z 24-120mm f/4S)

For lenses with only 1 control ring, ManualFocusRingInAFMode setting is disabled and cannot be toggled in camera menus, and whichever setting is set to the LensControlRing (M/A, ISO, EC, Aperture or Disabled), the setting would be applied to all single control ring lenses attached to the body.

For lenses with a control ring and focus ring, ManualFocusRingInAFMode setting can be toggled in camera menus, and similarly whichever setting chosen for LensControlRing would be applied to all double-ring lenses attached to the body.

It seems like the Exif data being reported is from the innate "Set B" settings, even if a "Set A" lens is attached to the body - so I am not sure if this is how the camera is writing the metadata to the files, or if there is a way to retrieve the Set A metadata from the files.

[StarGeek]

This sounds like a problem with the camera's firmware. Exiftool is just reporting the data that it reads.

You can run exiftool with the -v3 (-verbose3) option and it will show you exactly what the data in the file is.

For example

Code Select Expand

  | | | | | Beep = 0
  | | | | | - Tag '3.1', mask 0xc0 (1 bytes, int8u[1]):
  | | | | |     1d5c: 06                                              [.]
  | | | | | NoMemoryCard = 0
  | | | | | - Tag '3.2', mask 0x20 (1 bytes, int8u[1]):
  | | | | |     1d5c: 06                                              [.]
  | | | | | ISODisplay = 0
  | | | | | - Tag '3.3', mask 0x08 (1 bytes, int8u[1]):
  | | | | |     1d5c: 06                                              [.]
  | | | | | FileNumberSequence = 1
  | | | | | - Tag '4.1', mask 0x08 (1 bytes, int8u[1]):
  | | | | |     1d5d: 0c                                              [.]
Take a picture with each lens and look for that tag in each file and compare the underlyig data.

[fluffycat]

Thanks for the suggestion. Did not know about the verbose option until you mentioned it!

Anyway comparing the data across a few files with different settings, it seems that you are right - the EXIF written by the camera is wrong, and "80) LensControlRing = 4" does not change regardless of what settings I input in the custom options.

My apologies for thinking that it might be a bug with the Exiftool readout.

[Phil Harvey]

It is likely that the decoding for this could be wrong.  These settings sometimes change for different models, and some of these at least were decoded for other models, not the Z6.

Any input you could provide about settings specific to the Z6 would be helpful.  Specifically, if you run through all of the Func2Button settings and give the -n values for each setting I can update this for the Z6.  The same goes for other settings.

- Phil

[fluffycat]

Hi Phil,

I have ran through the 40 settings applicable to the function button, and tabulated the results in this attached txt file.

The first 16 entries on the list are OK - the custom setting coincides with what Exiftool reports.

The 17th entry "Subject Tracking" has the same n value as the AF-ON entry, and as such Exiftool reports AF-On.

From the 18th entry onwards everything is out of sync.

Hope this information might be useful!

[Phil Harvey]

Thanks.

Looking at your table it seems that AF-ON and "Subject tracking" both have the value 1.  Is this correct?  If so, ExifTool can't distinguish these.  And the value of 21 seems to be missing from your table.

Other than these problems, I could add proper decoding of this value for the Z6.  (Assuming these are consistent across firmware versions. -- Do you know if there was a firmware update the affected the function button?)

Also, I'm assuming this also applies to the Func1Button (not just Func2Button).  Can you confirm?

- Phil

[fluffycat]

Hi Phil,

Thanks for getting back.

Yes from my testing both AF-On and Subject Tracking show value 1. Might be an error from Nikon's side I guess.

There are a few gaps (like 23 missing too), so I am not too sure of the significance of the omission of 21.

Subject tracking function was added in firmware 3.00, which I think was released in 2020. Apart from that I don't think any new mappable functions have been released for the Z6.

I am actually out of town for an assignment and would only be back next week, so I'll double check and update you again when I'm back home regarding Func1button values.

Cheers!

[Phil Harvey]

It sounds like Nikon did mess this up with the 3.00 firmware update.  Could you send me a sample image (philharvey66 at gmail.com)?  I should be able to add a firmware-specific decoding for these tags.

- Phil

[Phil Harvey]

I've downloaded the Z6/Z7 2018 manual.  It looks like the decoding for this has been wrong all along because the manual corresponds to the settings you have mentioned.  These tags were decoded for the Z7ii, and it looks like we assumed it was the same for earlier models, but apparently it wasn't.  The 2018 manual does mention the Subject Tracking setting.  I think it makes sense to change the decoding for both Func1Button and Func2Button for the Z6 and Z7 according to the values you provided.  Thanks for this.

There are likely some other settings that are decoded incorrectly as well.

- Phil

[fluffycat]

Hi Phil,

Sorry for the late response as I just got home last night from my assignment.

I've run through the settings on Func1Button, and the values are indeed identical to Func2Bbutton, giving rise to identical errors for settings after the "Subject Tracking" function.

I have uploaded the 40 RAW files that I used to test out the Func2Button values and will send you the link via e-mail separately.

Hope the information helps!