How does electronic night mode work?

[grimloktt]

I'm familiar w/ IRs enabling video at night but what does Dahua mean when they say night (electronic)?

http://www.dahuasecurity.com/products/ipc-hdb4200f-pt-707.html

 

[Kawboy12R]

I read "night (electronic)" as jargon for "night (lousy)". No IR cut filter so it doesn't see IR day or night. Fine if the sensor's low light sensitivity works out with the lowest ambient white light level where the camera is used but don't expect it to use or see any IR present. Cam can switch to B&W mode at night though.