# VOXL2 Camera Calibration fails and bad QVIO tracking

Source: https://forum.modalai.com/topic/5363/voxl2-camera-calibration-fails-and-bad-qvio-tracking
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2026-08-04 21:45:20 UTC by kmuenpra
Replies: 0 · Views: 97

## kmuenpra · 2026-08-04 21:45:20 UTC

# **Drone specification:**
I am currently using Starling 2 Max with 
- Dual 4k & Dual Tracking & ToF (C29)
-  Microhard pMDDL2450 WiFi 
-  Ghost Atto 2.4GHz 
- **SKU: MRB-D0012-4-V2-C29-M11-T9-K3** (NOTE: This SKU is from the order receipt, which is different from the one shown when connected to the drone)

```
system-image: 1.8.06-M0054-14.1a-perf
kernel:       #1 SMP PREEMPT Wed Oct 22 04:13:18 UTC 2025 4.19.125
hw platform:  M0054
mach.var:     1.0.1
SKU:          MRB-D0012-4-V2-C29-T9-M22-X0
voxl-suite:   1.6.3

```

# **Cause:**
I recently flashed my VOXL2 board by following ["Unbricking your VOXL2" page](https://docs.modalai.com/voxl2-unbricking/). This wipes all calibration files, of which I generated new ones by calibrating the drone again. 

However, I am having issue getting a successful camera calibration with the same error every time:

```
Re-projection error reported by calibrateCamera: 1.26416
Calibration Failed
Max reprojection error: 0.60
This is most likely due to motion blur, please try again.
Exiting Cleanly
```

I have tried to debug by following these suggestions below:
https://forum.modalai.com/post/22010
https://forum.modalai.com/post/22066
https://forum.modalai.com/post/21909
However,  none of these fixes the max reprojection error. 

Finally, I manually write the files:
-  /data/modalai/opencv_tracking_front_intrinsics.yml 
-  /data/modalai/opencv_tracking_down_intrinsics.yml 

by using the camera matrix from the trial with smallest reprojection error (close to ~0.6).

# **Current Issue:**
My problem now is that, since the calibration files use bad camera matrices, the qvio tracking of the drone is inaccurate and drifts a lot. Here, I tested the front and downward camera by walking around in circle and returning the drone to the exact starting position. The result shows a lot of drift in both *qvio_extended* and *ov_extended*
![Screenshot from 2026-08-04 17-23-29.png](https://forum.modalai.com/assets/uploads/files/1785878640350-screenshot-from-2026-08-04-17-23-29.png) 

My questions are:

* Could the reflash have altered camera driver versions, exposure/gain settings, or `voxl-camera-server` config from factory defaults?
* Is there a way to compare my current per-camera intrinsics files against known-good factory defaults for the M0054 platform?
* Are there other config I should try to change to aid the camera calibration process?
* Is there any other open-source code that allows me to manually calibrate the camera?

Thank you for your time and help!