Incorrect decoding of Nikon Z6 III AFInfo?

[capricorn]

A user of Focus-Point Plug-in for Lightroom reported that the plug-in doesn't work for Nikon Z6 III images.

I checked this and found that the AFInfo2 section did not contain the expected information to determine the focus point used to capture the image. No coordinates for ContrastDetectAF (AF Area Height, AF Area Width, AF Area X Position, AF Area Y Position), no valid information for PhaseDetectAF. In fact, the AF-Point related information was the same for a number of images I reviewed.

Is there any chance that there is an error in decoding of AFInfo2 information for this camera?
I used exiftool 13.10.

For your reference, I'm attaching a number screen shots for AFInfo2 section for different Nikon Z camera types.

A sample image to can be downloaded here.

Thank you,
Karsten

[Phil Harvey]

To properly decode this I will need a set of sample images with known AF points and a sample for each different AF setting.

You can send samples to philharvey66 at gmail.com

- Phil

[capricorn]

Apart from various sample NEF images and NX studio screen shots showing the focus point, which other information would you need?

I neither own this camera, nor am I a Nikon shooter so I would need to work with somebody else if the above is not sufficient. What I currently have is a set of 36 NEF files downloaded from the dpreview sample gallery. Drawing conclusions from the EXIF data is difficult, since exiftool displays identical AFInfo2 section for all these files (except FocusDistance).

P.S.: This issue is not camera-specific but seems to be linked to AFInfo2 version. It's the same for Nikon Zf (same AFInfo2 version 0401) and the fairly new Z 50 II (0402). NEF files with 0400 (Z8, Z9) are ok.

[Phil Harvey]

For some settings we need to have samples from someone who has access to the camera.  For AFPoints we may be able to use NX Studio with existing samples as you mentioned.  I'll take a look at this when I get a chance.

The procedure is to compare the -U output for images with known settings.

- Phil

[capricorn]

OK, understood. If you agree, we could start with looking into basic inconsistencies in decoding of Contrast vs Phase-Detect AF information. Which is something that the camera user cannot directly influence via settings but it's a camera decision. And which is my primary interest to be able to draw the focus boxes

Would you prefer to take the further discussion offline to mail, or continue here?
(files will be supplied via Dropbox anyway)

[Phil Harvey]

Hi Karsten,

I'll contact the person who has been doing most of the Nikon Z-series decoding and get back to you.

- Phil

[Phil Harvey]

I got your mail, and have forwarded it to our Nikon Z expert.  He may contact you directly if he has any questions.

- Phil

[capricorn]

Decoding of AF2Info version 0401/0402 works in v13.12 👍
The remaining issue found (not able to modify "AFPointsUsed" tag) has been solved in v13.17 👍

Many thanks for the great support! 👍👍

Thank you,
Karsten