New cams may be coming with newer firmware than what's available on the Dahua site.
If not, there is currently a bug in the firmware that prevents the
IR light to work correctly when zooming.
And the auto tracking is very hit and miss. Firmware update will hopefully fix this.
Take a look here:
2 Megapixel - Dahua Technology
and here:
2 Megapixel - Dahua Technology
IVS allows you to setup virtual lines in the camerea that if something cross's those lines, that triggers the cam to record or react to the way you have it setup;.