# Flying in poorly-lit conditions

Source: https://forum.modalai.com/topic/589/flying-in-poorly-lit-conditions
Category: Flight Core and Legacy VOXL (https://forum.modalai.com/category/9/flight-core-and-legacy-voxl)
Tags: voxl-flight
Posted: 2021-12-02 18:33:13 UTC by Lynn Koudsi
Replies: 4 · Views: 1676

## Lynn Koudsi · 2021-12-02 18:33:13 UTC

We are using the M500 in poorly-lit hallways with a dark void. Even though we've installed lighting on the drone, we still weren't able to get a stable position control status, it kept falling back to stabilized mode. If we fly the drone sideways facing the walls of the hallway, it flies much better (obviously, since it gets more odometry that way). So we're thinking of possible solutions:

* Rotate the tracking camera 90 degrees to face the walls of the hallways instead of the front, or move it to the side. That would keep the stereo cameras facing forward for offboard mode.
* Switch the RC channels so that our forward is the drone's side, but that means the stereo cameras would also face the side. This wouldn't allow us to use offboard mode, so we would either need to move the stereo cameras to the front, or use a little LIDAR instead. 

Any thoughts or technical notes on the previous points?

## Reply by Chad Sweet (ModalAI staff) · 2021-12-02 18:56:29 UTC

A few thoughts:

* You can tweak the exposure settings to be biased towards your use case (see [here](https://docs.modalai.com/voxl-camera-server/#exposure))
* No problem rotating 90°. You will **need** to re-configure the extrinsic parameters or VIO won't work. See [here](https://docs.modalai.com/configure-extrinsics/)

## Reply by Lynn Koudsi · 2021-12-02 19:52:08 UTC

That makes sense, thank you! We will try to tweak the exposure settings before making major changes to the unit.

Another idea we were discussing that kind of relates back to our problem, is to add another tracking camera to the voxl system for redundancy. Technically and physically speaking, is there anything that would stop us from achieving that? 
I'm thinking we would need to run another instance of voxl-vision-px4 and create a component that will consolidate the results of both, falling back on one if another fails. 

Any thoughts on that?

## Reply by Lynn Koudsi · 2021-12-21 15:20:35 UTC (in reply to Chad Sweet)

@Chad-Sweet I referenced the forum post linked [here](https://forum.modalai.com/topic/383/changing-default-cameras?_=1640098876611), and after some more investigation I found that it's not possible to add an extra tracking OV7251 camera onto the system. However, I'm wondering if it's possible to add a different model of camera alongside the stereo and tracking cameras

## Reply by Chad Sweet (ModalAI staff) · 2021-12-21 19:40:54 UTC

The list of supported camera configurations is [here](https://docs.modalai.com/camera-connections/)

I think you would want to run a second qvio-server and merge the results in vvpx4

You could use one of the stereo sensors for that today and point the tracking sensor in a different direction