Oil pressure Question: What causes this?

DING DING DING....We have a winner.

I disconnected the oil kit and spun a block filter on, and drained about 1 qt of extra oil I had in the crankcase (to fill up the lines to the filter mount). Now the car is pushing proper pressure and the pressure increases with RPM.

So now the task is to find out if there is a problem with one of the oil filters I just installed during this oil change, or if I just didn't have enough oil in the crankcase to pressurize the lines when they drain back.

Either way, I'm comfortable driving it now knowing it's not an impending engine problem.