#1342 Exposure in repeat mode sporadically goes haywire

[Michael von Glasow]

To reproduce:

1. Select Repeat mode with an unlimited number of photos and an interval of 1 second.
2. Choose the highest resolution offered by the camera.
3. Make sure exposure lock is off.
4. Mount the camera in a vehicle so it works in a manner similar to a dash cam.
5. Start taking pictures.

Expected result:

One image taken approximately each second, with a suitable exposure setting.

Actual result:

Sporadically, after taking pictures for some time, the exposure suddenly starts to act up, and the camera oscillates between complete underexposure and complete overexposure, to the point of images being completely or almost completely black or completely white.

Two factors seem to influence this behavior:

• weather conditions – the problem is more likely to occur in sunny weather than when the sky is cloudy – presumably because changes between light and shadow require exposure to be adjusted more frequently
• processing load on the device (postprocessing, heavier JPEG compression, larger image size) seems to be a driver – the issue is more likely to occur with high resolution, high compression and postprocesing (e.g. DRO) enabled

Part of the problem seems to be system load – taking a 5 MP picture each second may push the system to its limits. Since load seems to play a factor here, I suspect the app tells the camera not “adjust exposure by n notches up” but “crank exposure up until I say stop”. If the system is overloaded, the camera has already overcorrected, and the app corrects again, this time in the other direction, again overcorrecting and the cycle repeats.

If there is any way to change exposure by a fixed amount or set it to a fixed target, instead of “crank it up until I say stop”, this might solve the problem.

System information:

OpenCamera 1.55 (from F-Droid)
Android 11 (LineageOS 18)
OnePlus One

[Anonymous]

Update to the latest version (v1.56.2) and check there

[Michael von Glasow]

I don’t see that version on F-Droid yet, any ideas when it will be available?