Minimum frame rate?

[flw 0]

Hi,

 

I am setting up a new PC based DVR system with 3 cameras. The usage is to monitor my young child at home with my helper. Just to make sure he does not get bullied or the helper does not leave him alone when I am not around.

 

What is the minimum frame rate with a 4CH card? Also, if I am using only 3 cameras, can the card frame rate be divided by 3 instead of by 4?

 

 

Thanks,

FLW

[Scruit 0]

There are too many cards out there to tell you what framerates are unless you look at a specific manufacturer,

 

I will add that he more expensive brand-name cards will have more of the video processing onboard using hardware which reduces the load on the PC's CPU. Cheaper cards (ebay specials) will rely on the CPU to do the processing and that makes the framerate lower and the PC is usually running at 99% CPU usage all the time.

 

As far as watching your child... Make sure you know your local laws on privacy and CCTV, especially as relates to audio. There are some rooms that may be off-limits also. You need to use the highest framerate you can get because situations involving physical struggles between people are generally very dynamic and fast-moving scenes that would be difficult to prove with a low framerate. I know of one nanny-cam case where the low framerate of the camera caused the footage to be thrown out. It was something like 3 or 4 FPS and the judge said the "shaking" that the video showed could have been misinterpreted. In your situation I'd say at least 15fps is what you need.

 

My home DVR runs at a lower framerate (10fps) but runs in full quality because it's intended to provide evidence to help track down the bad guy and the higher framerate is not needed to be able to tell exactly what the BG is doing (ie If he's walking out the door with my TV!). In my car the DVR is set at lower quality (CIF) and higher framerate (realtime/30fps) becuause car accidents can be very dynamic and fast-moving (just like physical altercations) and a low framerate video may give the viewer an inaccurate perception of the incident. It's unlikely my footgae will help track down a hit/run unless the video catches something unique about the other car. The license plat would be nice but getting that on film is too much of a challenge given consumer-level off-the-shelf technology. Maybe an 8mp cam running through a fisheye lens with dewarping software...