Does overt or covert depend on the time of day?

This Lancaster (PA) case illustrates a few points about using CCTV evidence in trial.

Cameras mounted outside of a business were used in recording some activity that the prosecutor wants to use in trial. The essence of the defense's objection is that the defendant couldn't see the cameras - it was 1am and quite dark. Thus, with the lack of lighting, does overt placement become covert? Hmm.

Additionally, the CCTV system had an active microphone that recorded the defendant's conversation in the public space, which may be a crime in itself.

Lots of issues at play in this murder trial.