Thank you for your time and advice.
For the ELP 720P: rtsp://192.168.0.158:556/user=admin&password=&channel=1&stream=0.sdp?real_stream
For the Escam QD520: rtsp://192.168.0.159:555/user=admin&password=&channel=1&stream=0.sdp?real_stream
Each camera has a 3.6 mm lens.
The Escam QD520 is a little more expensive, but its night range is significantly farther than the ELP.
I am trying various formats as you suggest for the Hosafe 2MD4P-36, but haven't found one that works. The Hosafe is not a PTZ. The improvement of night range and the resolution over the Escam QD520, is very significant -- well worth the additional expense. The field of view seems to be wider than the 3.6 mm but the spec states 3.6. But the resolution is much sharper even at the apparent wider angle. It has 36 IR LEDs
The Hosafe does not require a password (neither do the ELP and Escam). Should I add one just for the sake of WebcamXP? Do you have any other suggestions for URL format?
And from the VLC Codec specs, do you think the Hosafe should work with Netcam Studio and WebcamXP and the "Universal Source Filter 4.6"?
I did find two Moonware filters. Maybe one is just newer than the other. I have only tried the "16,861 KB" version:
musf-x86 webcamXP universal filter.exe 16,861 KB
musf-x86.exe 14,774 KB
Again, thanks Henrik,