I was previously unaware of iFrame's. I usually don't mess with the camera settings, I do everything through the NVR gui.
The NVR gui doesn't show iFrames, unless it is buried somewhere that I missed. My NVR (& camera) show 4 settings: Main Stream, Sub Stream,
Main Stream Event, and Transcode (I don't know what that is).
This is the settings at a camera for Main Event:
This is the same camera, Substream:
I have 10 cameras that I display all at once on a 4x4 grid on a TV at the NVR. These settings match the NVR settings, except for iFrame, which is not on my NVR.
I rarely use the browser to access the cameras.
The Main Stream Event currently has the same settings as the Main Stream(Normal), shown above.
On one of my camera's I had the Main Stream resolution mistakenly set much higher and I had issues with it.
Once I realized that other camera's were set to 1920x1080P and changed it to match, things are working better.
Since my TV is 1920x1080P I think this is a good setting for resolution. For a computer monitor a higher resolution might be better, just a wild guess.
I also recently had issues with capture of events to usb stick, I need to test that functionality again to make sure it works well on all cameras.
It *might* be that I should increase the resolution on Event recording, but not sure how that will turn out.
I do on occasion notice an object detected by motion suddenly appear in the middle of the view and sometimes, disappear before
the end of the view. I assume this is a function of motion sensitivity. These objects are all further away, beyond the range of
the IR lighting so I have not tried to change the sensitivity because at night I would not be able to see what is causing it to record.