Generally, industry people know significantly less about CCTV / video surveillance than they think they know. I attribute this to 2 factors:
- There is no formal education coming into the industry so everyone is forced to pick it up on their own, so the variation in core knowledge is immense (most just get a smattering of on-the-job experience and vendor sales presentations).
- The technology does significantly change, so the in-depth learning you might have had in 2008 about CCD imagers and coaxial cable (e.g.) is not only less relevant but can lead you to make wrong decisions in 2018. Related Beware Out of Date Knowledge
As for how in-depth one should go that depends on one's role and one's ambition. Someone wanting to design and manage enterprise systems definitely would benefit far more from in-depth learning than an installer for residential systems.
Our two books (including for all members) can help: 2018 Camera Book and 2018 IP Networking Book.