Which resolution should I use for Dahua 4MP camera?

alecz

Young grasshopper
May 16, 2023
63
13
Montreal
I have a mix of Dahua 4MP cameras (1 IPC-HDW5442TM-AS-LED and a couple IPC-HDW2439TP-AS-LED-S2)
In the resolution drop down for the main stream I have
  • 2688 × 1520
  • 2560 × 1440
  • and lower
Which resolution should I use? Which one is the actual "native" camera resolution?

What I noticed is that when I switched from 1440 -> 1520, the image appeared to zoom out, so what I suspect is that these cameras have native 2688 × 1520 and when I select 2560 × 1440, they crop the extra pixels (rather than downscale), but I am not sure.

I am recording this in BlueIris and I don't care much about aspect ration, but I don't want to choose a resolution that will downgrade image quality.

So which resolution should I use for(these) Dahua 4MP camera? The HDW5442TM is very popular on this forum, what do people set it to (and why)?
 
2688x1520 is full 4MP resolution at near 16:9 aspect ratio.

I found this thread when doing a quick search.