Is there a Maximum Exposure Limit for Stereo Cameras?

[Shreyansh Daftry]

We are unable to manually set the exposure of the stereo pair (M0072 with IR filters) higher than 17ms. While it does not throw an error, it defaults to 17ms every time we use the voxl-send-command with value greater than 17.

Is this a limitation imposed by the camera driver or is this a sensor limitation itself? At 17ms exposure, the images are too dark indoors. If this is not a sensor limitation, Is there a way to modify the driver to allow for setting exposure greater than 17ms. We have the flexibility to reduce camera frame rate to a lower value (as low as 1 hz. Currently streaming at 30fps)

[Moderator]

@Shreyansh-Daftry @Shreyansh-Daftry In short no, there shouldn't be. Which hardware and software version are you using? It seems you are not setting gain as well? 17ms exposure should be more than enough for indoors, maybe your gain is too low?

For VOXL 2, the next version of the SDK will have updates in this area.

[Shreyansh Daftry]

Thank you for the response! I used a gain of 998, which was the max it would allow; anything over that values defaults to 998.

Here are the details of my setup:

• Hardware: VOXL2 board, Stereo cameras (pair of MSU-M0072-2-00 Tracking Camera with IR Filters)

• Software version: See output of voxl-version command below. I believe we are using the older 0.9 version of the SDK, which might have some issues with camera exposure commands (based on other posts on this forum). Also, looking at the code, I did find that src/config/config_defaults.cpp file has a min/max exposure for the OV7251 cameras to be 20 (=0.02ms) and 33000 (=33ms).

Also, a related question: the voxl-send-command exposure units are in Millisecond, correct?

---

voxl2:~$ voxl-version

system-image: 1.5.5-M0054-14.1a-perf
kernel: #1 SMP PREEMPT Fri Mar 24 00:48:55 UTC 2023 4.19.125

hw version: M0054

voxl-suite: 0.9.5

Packages:
Repo: http://voxl-packages.modalai.com/ ./dists/qrb5165/sdk-0.9/binary-arm64/
Last Updated: 2023-07-16 21:20:58
List:
libmodal-cv 0.2.3
libmodal-exposure 0.0.7
libmodal-journal 0.2.1
libmodal-json 0.4.3
libmodal-pipe 2.8.2
libqrb5165-io 0.1.0
libvoxl-cci-direct 0.1.5
libvoxl-cutils 0.1.1
mv-voxl 0.1-r0
qrb5165-bind 0.1-r0
qrb5165-dfs-server 0.1.0
qrb5165-imu-server 0.5.0
qrb5165-slpi-test-sig 01-r0
qrb5165-system-tweaks 0.1.5
qrb5165-tflite 2.8.0-2
voxl-bind 0.0.1
voxl-camera-calibration 0.2.3
voxl-camera-server 1.3.5
voxl-cpu-monitor 0.3.0
voxl-docker-support 1.2.4
voxl-gphoto2-server 0.0.10
voxl-jpeg-turbo 2.1.3-4
voxl-libgphoto2 0.0.4
voxl-libuvc 1.0.7
voxl-logger 0.3.4
voxl-mavlink 0.1.0
voxl-mavlink-server 0.3.0
voxl-modem 0.16.1
voxl-mongoose 7.7.0-1
voxl-mpa-to-ros 0.3.6
voxl-mpa-tools 0.7.6
voxl-opencv 4.5.5-1
voxl-portal 0.5.0
voxl-px4 1.12.31
voxl-px4-imu-server 0.1.2
voxl-qvio-server 0.8.2
voxl-remote-id 0.0.5
voxl-streamer 0.4.1
voxl-suite 0.9.5
voxl-tag-detector 0.0.4
voxl-tflite-server 0.3.1
voxl-utils 1.2.2
voxl-uvc-server 0.1.3
voxl-vision-px4 1.4.0
voxl2-system-image 1.5.5-r0
voxl2-wlan 1.0-r0