If you point the camera at the sun in daylight, I would expect the exposure probably to go down to the minimum possible for the sensor, but for the image still to be completely over-exposed. I guess it might depend on how bright it is that day, and maybe you could mitigate this with an ND filter.
For night time pictures, I don't think ev -3 will help. It will be "wanting" a mid-level exposure image, but at night the actual image will be virtually zero everywhere. So even asking for 1/8 (ev - 3) times the default exposure will still be way more than it can deliver, so the exposure time - and all the image highlights - will completely max out. I think you'll have to set fixed exposure and gains.
I think setting channel 0 to be the HDR channel, and then using fixed exposure/gain might work. In case you haven't found it, go to the imx477.json tuning file, find the "SingleExposure" section in the "rpi.hdr" algorihtm and then change the "short" channel and "cadence" numbers from 1 to 0.
For night time pictures, I don't think ev -3 will help. It will be "wanting" a mid-level exposure image, but at night the actual image will be virtually zero everywhere. So even asking for 1/8 (ev - 3) times the default exposure will still be way more than it can deliver, so the exposure time - and all the image highlights - will completely max out. I think you'll have to set fixed exposure and gains.
I think setting channel 0 to be the HDR channel, and then using fixed exposure/gain might work. In case you haven't found it, go to the imx477.json tuning file, find the "SingleExposure" section in the "rpi.hdr" algorihtm and then change the "short" channel and "cadence" numbers from 1 to 0.
Statistics: Posted by therealdavidp — Mon Mar 25, 2024 9:39 am
