GrouchoBoucho

20gb should take well under 10 minutes via usb 2.0 (http://adamsworld.name/copy_calc.php puts it at 06:15). when you insert the drive into the home machine, the system will make it a mirror for the existing drive and overwrite it. run away!

you have to physically access the machine to swap two of them anyway... i'd just use the backup-to-external-disk method in that case. much easier to carry a usb disk on and off site than an entire nvr.

try this calc: http://www.pelco.com/sites/global/en/sales-and-support/downloads-and-tools/tools/lens-calc.page 17cm = 0.558' 80cm = 2.625'' select 1/4" camera, put 0.558 for the height (since the camera view is wider than it is high), and you get about a 12mm lens (view will be about 23cm wide). (and actually, you can just plug in 17 and 80 for the image height and distance, and get the same results - the units aren't really relevant as the two measurements are the same relative to each other) given the height above the target, the actual distance will be a little more, and the target won't appear square in the frame anyway because of perspective distortion... not much you can do about that without getting into a tilt-shift lens. a better idea would be simply to get a better camera with a varifocal lens, so you can adjust the focal length until the view fits the way you want. 3-33mm lenses are relatively common and should cover any size sensor at any distance or angle in your range.

fps with ip cameras will still be limited by your network and pc hardware, so don't expect going to ip to be a magic fix for the issue if your network is overloaded or your pc is too old and slow.

this is the best you can expect from the cheap gear you got.

wow, doesn't sound like any kind of conflict of interest here *at all*

there are lots of ip cameras (yes, including hd) that have built-in recording to sd card that will give you hours, days or weeks of recording. most can be powered from 12v and run separate from any recorder - you just plug in your laptop when you want to view the video. i've seen 1080p domes starting around $200.

cameras with heaters also have thermostats so the heaters only come on below a certain temp. a fan inside a sealed enclosure won't cool the camera at all; all it does is circulate hot air around. neither of these are designed to keep the camera warm OR cool - they're there specifically to keep the glass clear of condensation.

did they actually use baluns or are the wires just spliced in directly? if they did use baluns, did they use only one pair for video? sounds like something else is goofy. maybe the cameras are failing?