Power & Source of Big Ideas

Long exposure with OV13850 MIPI?

Moderators: chensy, FATechsupport

Hi all :)

Does anyone know how to control the frame exposure time for individual photos? I have the 13mp OV13850 and it should, theoretically, be capable of ~35s exposures. From the OV13850 datasheet:

> If OV13850 works at 120MHz, the maximum exposure time is 35.79 sec.

I've been playing around with both v4l2 and gstreamer but can't seem to get an exposure other than what's used in the demo scripts (1/10, 1/30). I also can't seem to access the full resolution through gstreamer either, 4224x3136 always hangs no matter what I do.

I was able to capture a raw image via v4l2-ctl at full resolution, but the exposure setting through v4l2-ctl says the maximum is "1664" which I think is in microseconds, and so not very long :)

Anyone know how to get longer exposures? Or is the firmware/driver for the OV13850 just broken and unable to expose for longer?
I restarted the RK3399 and opened the CameraExample app to find that only the video stream from the modified camera was appearing. But that one video stream focused and auto adjusted for exposure and white balance perfectly. The video stream from the unmodified camera was completely black however the app still displayed that the camera existed. I then opened the normal camera app and both cameras still appeared as front and rear and worked just as they did before any modification. So, I think this means that both cameras operate correctly (including independent focus, exposure and white balance) however I can not record two video streams at the same time.
Tutuapp 9apps Showbox
The video stream from the unmodified camera was completely black however the app still displayed that the camera existed. I then opened the normal camera app and both cameras still appeared as front and rear and worked just as they did before any modification.
sakija wrote:
I restarted the RK3399 and opened the CameraExample app to find that only the video stream from the modified camera was appearing. But that one video stream focused and auto adjusted for exposure and white balance perfectly. The video stream from the unmodified camera was completely black however the app still displayed that the camera existed. I then opened the normal camera app and both cameras still appeared as front and rear and worked just as they did before any modification. So, I think this means that both cameras operate correctly (including independent focus, exposure and white balance) however I can not record two video streams at the same time.
Tutuapp 9apps Showbox


thats a big problem

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