Camera pairing accuracy 0 with orbbec femto bolt and sony

Today we created a rig similar to the one in your documentation:

camera-rig4000×2250 437 KB

and set the zoom lens to 16 mm (because the sensor is 36*24 mm).

Then we created succesfully the lens correction profile which we could succesfully use in the calibration step inside of Depthkit, when doing the pairing process.

We have tried the pairing three times. Two times with another rig construction (where the camera lens and the sensor lens were exactly vertically above each other, but quite far away. Then, because the pairing result was always “BAD”, we changed the rig-construction to attached photo.

We again started the calibration: always covering all four quadrants of the image, at three different distances from the calibration chart. But still the result says “BAD”.

The calibration chart stood always at the same position and rotation. Untouched. We only moved and rotated the camera rig in space. Maybe we should have kept the camera rig untouched and just move the calibration chart in space, covering both lenses and quadrants?

Also we had a hard time seeing the white alignment indicators, because the contrast and exposure may have been too high. But that worked best for detection the chart.

Have you any more advices than what is already written here?
https://docs.depthkit.tv/docs/camera-pairing#how-do-i-read-my-pairing-evaluation

What information can I get from these numbers?
https://files.readme.io/f30f849-samples.PNG

@JanFiess / Nick - Thanks for posting here. I have had a chance to look at your project, and have a couple of recommendations:

image1121×416 95.9 KB

• In 13 of the 19 samples, the calibration board is clipped by the edge of the depth camera’s frame/vignette, leaving only 6 valid samples. The entire pattern needs to be in frame for it to successfully be detected and registered. In the Pairing documentation, we recommend setting the depth sensor to the WFOV Raw mode to avoid this during pairing, then switching it to NFOV when it comes time to record a capture.
• The Pairing Sample images do indeed look a bit overexposed, and many of them are not sharply focused on the calibration pattern. If the corners of the squares are not in sharp focus, Depthkit cannot detect their position, so make sure you re-focus the lens each time you move or rotate the camera/chart before capturing that sample.
• The Sony video files in the CLIP folder - which appear to be the video clips from which the Pairing samples were pulled - are 1920x1080 resolution. Not only is this a lower resolution than the RGB video from the Orbbec sensor, but it is also harder for Depthkit to detect the calibration markers at 1080p than at a higher resolution like 2160p. If this is how the camera recorded them, I recommend retrying the entire Lens Profile & Cinema Pairing process using a higher-resolution codec like XAVC S-I 4K. If the camera recorded at a higher resolution like 4K, it’s possible that this downscaling took place during transcoding, so check your transcode settings to ensure that the original resolution is preserved.
• Not critical in this step, but I also noticed the Sony video files are recording at 59.94fps. For best results with recordings, select a framerate which most closely matches the sensor’s 30fps framerate, like 29.97fps.

Making these adjustments to resolution, exposure, focus, and framing should provide much better result on the next attempt. If you continue to get poor results, feel free to send an updated project folder with all of the materials you sent this time, but also include:

• The LCP/XML lens profile file
• The images used to generate the lens profile
• The Cinema camera video which accompanies any recorded takes.

I’ll keep a lookout for updates.

Thank you very much Cory. Much appreciated.
We’ll retest tomorrow and give you an update.

@JanFiess Great - keep us posted!

@CoryAllen The results are better now.
The lens calibration had no faulty images no more. Very good.

With this sample filtering we have lens accuracy at 56 % but lens coverage never higher than 38 %. I guess we should take more well spreaded samples?

But why is the pairing accuracy always at 0 %?

Screenshot 2025-06-17 232438567×585 38.7 KB

And my biggest question: is the rig (see picture at starting thread) good enough? Or are the lenses too far apart? Do you see any issues there?

And I am still confused about what these numbers mean and what to do…

Screenshot 2025-06-18 104313534×460 39.8 KB

We rebuilt the entire camera rig, so it’s mor similar to yours and the sensor and cinema camera are very close.
Recalibrated everything. The scores are now better.
But lens coverage will most likely never be better, due to the fisheye-lens. The lens coverage of the rgb femto bolt will be almost 100%. But the cinema camera lens coverage (fisheye) will not be. See overlayed image of the fisheye-videos:

WhatsApp Image 2025-06-20 at 17.24.031112×621 137 KB

WhatsApp Image 2025-06-20 at 17.24.03 (1)592×661 50.2 KB

Strange: sampled volume is significantly lower, although I captured the same way as 3 days ago…
Why is the pairing accuracy always 0???

These are all improvements, even if some metrics seem to indicate otherwise. Most importantly, how does the texture from the camera align with the mesh when you enable Cinema on a recording? How it looks visually is more important than any of these metrics, so if things align to your eye, stick with that pairing.

Apologies for not answering your question in the initial post - The breakdown is as follows:

Pairing Sample 14 - the ID of the sample, in this case 14
🟤 - gives a quick visual ranking of the error score of that sample based on the current solution. Brown/Red is bad; Yellow/Green is good.
9.7616 - the numerical error score of that sample based on the current solution. Lower is better.
65 - The number of grid crosspoints detected in the sample. Higher is better. Low indicates the sample was too far/blurry/distorted/bright/dark to be fully detected.
✅ - For any samples with a particularly high error score and/or low crosspoint count, you can manually exclude each of them by unchecking this checkbox, then clicking ‘Pair Camera’ again to see if the scores for the remaining samples improve.

@JanFiess / Nick - Any updates on this issue? Were you able to assess the calibration visually? Let me know if you still need assistance - Otherwise I will close the ticket.

Hi Cory

The pairing was visually fine. So we went on with that calibration and recorded 5 days with this. Looks as expected. So not really a problem showing “BAD” and “0 accuracy”. But very irritating and made me calibrate three times, what is in the end pretty annoying.
But thank you very much for always being helpful! Really appreciate it!