# RGB Camera Info

Source: https://forum.modalai.com/topic/5190/rgb-camera-info
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2026-05-01 02:24:56 UTC by james.emi
Replies: 1 · Views: 190

## james.emi · 2026-05-01 02:24:56 UTC

I am trying to get the camera intrinsics for the onboard RGB camera for the Starling 2 drone. From the product spec I can see that it has the IMX412 color image sensor, but can't find the lens information (I need a focal length estimate and ideal 'camera model') to calibrate using the kalibr tool. Any help / guidance would be appreciated! Thanks in advance :)

## Reply by Alex Kushleyev (ModalAI staff) · 2026-05-11 22:03:04 UTC

@james-emi ,

In our `voxl-camera-server`, we have a default intrinsics config for the IMX412 camera / lens as follows (focal length approximation is based on a several calibrations). Basically it is a fisheye lens with about 2000px focal length at full resolution (half of that at half resolution, etc). The camera full sensor width is 4056 (hence the x principal point is exactly half of that 2028). In some cases we use slightly trimmed frame (4040 in width). But in any case, that should be enough for a good starting point.

```
lens_cal.width  = 4040;
lens_cal.height = 3040;
lens_cal.fx     = 1999.0;
lens_cal.fy     = 1999.0;
lens_cal.cx     = 2028.0;
lens_cal.cy     = 1520.0;
lens_cal.is_fisheye = 1;
```

Alex