So, my initial thoughts are this:
1) The Dahua 5231 seems to have a bit better night vision coverage at the target range of about 38 feet or so, as you can clearly see the sign still visible and the tree above it.. but notice the clairity of all the grass and closer objects within the main FOV... they are not nearly as clear as the LOREX is in the under 38' range.
2) The LOREX seems to lose it's IR coverage around the 36' mark or so, you can still see the sign but it's dark, and then the trees behind it are real dark... But, look at the clarity of the objects closer, ie the grass, the cement slab at the right....
The overall clarity of the LOREX just seems to be much better? maybe I need to tweak things in the 5231 to get a better picture? I kept everything stock on both cameras, FYI.. I didn't change anything...
Also, Note, the LOREX does indeed have that IR LED right in the middle, it was clearly visible once dark out, you could see the glowing RED.. and the security WHITE LEDS were NOT ON at all... so they are totally separate from the IR electronics.
So far I am quite impressed, I like this lorex bullet.....you do lose some night vision range when compared to the Dahua, but under that 36' or so, it seems rock solid. I'll have to do some more tests with some targets like this again, but in a closer range at maybe 20' or something...