Apologies if this is pretty obvious but I haven’t had any luck after looking around. On the Dahua web interface, how do you confirm what the zoom level is set to, as it relates to focal length? Say I wanted to test what 6mm focal length looks like, how do I set the camera to that specifically? The Zoom slider shows numbers from 0 (Zoom in) to 2275 (Zoom Out). However, it doesn't state what the equivalent lens focal length is within 2.7-12mm range.