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hids2000

some questions regarding setting up a 4ch DVR

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I plan to have 4 color cameras with IR all aimed at the front of our house. Our lot frontage is 50ft.

 

I am going to go with a 4ch DVR with 30fps per ch.

The DVR record resolution is 720x240(576).

 

from reading around on the forum I should get the highest resolution cameras. Based on 720x240(576) what should I get in terms of cameras, 420, 480, or 540? no point getting higher res cameras if the DVR can't record it.

 

from the front of the house to the street is about 15ft. I plan to get 1/3" sony super had cameras with 6mm lens. all 4 cameras will be aimmed at the front of the house to over lap each other. I read on the forum that IR cameras I should double my distance to be safe. In my case is 30ft. These cameras are rated at 120ft. Will the cameras IR lights be too powerful?

 

I also have a street light in front of house about 45ft away.

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Everything looks good so far!

 

You will have to test the cameras with that IR on your house to find out whether they are to strong or not.

 

You may find that they send out a very narrow beam, and by having four cameras shooting to the street that this may give you the wide IR coverage that you need.

 

Give it a try and let us know how it works!

 

I do not think a camera above 480 would be worth the money. I would suggest those if you have a high end DVR.

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You mention one thing that could cause a problem. The street light. If you use IR cameras, they may not turn on the IR diodes if you have too much light in the camera area. Buy one camera and experiment with it in each camera area. If it looks good, then buy your other cameras. I have been using small shatter proof domes that are tri axel with good results. Like another poster said. If they claim they will give you a good picture at 30 feet. Get a camera for 50 feet. The camera folks give you info under ideal conditions.

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The DVR record resolution is 720x240(576).

 

what should I get in terms of cameras, 420, 480, or 540?

 

Be aware that the camera resolutions you have mentioned refer to the horizontal direction and are "line pairs" of discernible resolution not pixels. With the DVR capable of digitizing the analog signal to 720 pixels, any of those cameras can be taken full advantage of.

 

But in the vertical direction you have provided conflicting numbers. 480 is the fixed number of actual lines provided by any NTSC camera, so the DVR is either compromising by "averaging" them down to 240 (quite common,) or there is a misprint and it's actually 480.

 

In either case the 576 number is for the full number of PAL lines vertically and (for NTSC countries) is not relevant. The reason the spec is quoted the way it is, with three numbers, is that 720 is sufficiently high for either NTSC or PAL.

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