Playing around with Raspberry Pi Camera Module V2 in low light

I've installed a Camera Module V2 (with the IR filter) into my nest box and Adafruit LED Sequins to light up the inside at night. Since I didn't want to shine directly at birds, I soldered the Sequins on the back side of the Raspberry Pi, sort of bias lighting.

The Sequins are tiny LEDs that draw only 5mA each, thus not bright enough for the camera. We're not going to disturb birds too much anyway, so here're some results for the camera picture with different settings at night.

All tests are performed at 3 Mb/s, 720p, night scene mode.

Baseline, daylight

Picture brightness depends on FPS as much as number of turned on LEDs.

1 fps, all 5 LEDs are on
5 fps, 5 LEDs
1 fps, 3 LEDs
5 fps, 3 LEDs
15 fps, 5 LEDs