The 3849 is a horrible camera that should have never been sold.
This is active deterrence camera on an 8MP on a
1/2.8" sensor, so it is on a horrible MP/sensor ratio. You cannot have enough light at night for it to perform well. That sensor is designed for 2MP so a 2MP camera will kick its butt all night long.
Even worse, since this 8MP is on the same sensor and CPU as a 2MP non TIOC camera and there are many threads here showing how under-performing that 3849 is. They had to limit bitrate and other parameters on the 3849 to try to make it functional, and it just doesn't cut it.
In my opinion the 3849 should not be sold with that current MP/sensor and CPU combination, but alas everybody wants 4k and chases MP over sensor and this camera is the epitome of that thinking.
Further, the red/blue flashing lights are more gimmicky and are certainly not a deterrent. With any ambient light you won't see the red/blue flashing unless you are looking right at the camera.
If you want active deterrence, your best bet is to go with the 2MP IPC-T5241H-AS-PV that will blink the white light. This is on the ideal MP/sensor ratio and will perform comparably to any similar 2MP fixed lens camera by Dahua. I have two of them. I have some of the other active deterrence cams as well, and would opt for the 2MP in every instance except for indoor, one could go with the IPC-HDW3449HP-AS-PV that has the red/blue lights that will bounce off the walls and be much more impressive than outside.
Lot's of threads here where people showed how bad the 3849 camera is in performing:
IPC-HDW3849H-AS-PV issues
IPC-HDW3849H-AS-PV loses connection/reboots during the day
Replaced HDW5442TMP-ASE by HFW3849T1P
Dahua 8mp (TIOC): Full Colour, Active Deterrence & AI
IPC-HDW3849H-AS-PV Video Quality