BTW (by the way) welcome to the Securifi forum Jbeaman.
Here I utilize Optex combo analog cams and they have built in PIRs. I power the camera with DC voltage and there are three sensors in it.
Lately too migrating all legacy analog cameras to IP HD cameras. Picture is way better.
That said I also do video analytics for motion trigger events using multiple defined zoning plus various methodology weighing:
1 - Sensitivity presets are:
Fast low sensitivity
Fast medium sensitivity
Fast high sensitivity
Best low sensitivity
Best medium sensivity
Best high sensitivity
2 - Alarm check methods
Blobs
Alarmed pixels
Filtered pixels
and more.
Algorithms are way better today than yesterday and much faster.
That said it still not a perfect science. It only works so so. Even the best and most expensive video analytics isn't right yet.
Here I depend on a combination of different technologies for outdoor motion and use them in combination to trigger alarm events and motion recording events.
A bird, fly, bee or rain or trees moving messes a bunch with video analytics. In the home its much easier to do than the outside.
Look at the attached picture; the lines you see are the video analytics.