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Thread: ir cctv camera noise problem?

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    Default ir cctv camera noise problem?

    I have 2 ir cctv cameras outside my house that are getting a grainy picture most noticeable at night when they go b/w.

    Now first thing that comes to mind is my elcheapo cameras are probably starting to play up but on further reading and research im wondering if i have some sort of interferance or a problem with the power supplies.

    One thing is when i first installed them a year ago, i ran the coax along the eaves ontop of the cement sheet.
    Along the path is the main power fuse box and the power comes out and also runs along the eaves next to where i run my coax.

    Could this be a reason for my grainy pictures?

    Any advice apreciated.



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    Can you try a different power supply or
    disconnect one camera and see if it makes any difference
    I had one dodgy camera and it made all 6 other cameras go grainy.
    When you do things right, people won't be sure that you have done anything at all

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    Yep could do, ive got a adjustable power supply that i use for my jaycar programmer that i might try.

    Im still thinking its interferance though.

    Last resort i might try to reroute the coax temporaraly away from the main power runs and see what happens.

    Maybe ill just pull one down and run it straight into my dvr to see if the picture is any better tomorrow.

    Just chasing opinions incase im missing something......

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    Your on the ball, Process of elimination
    When you do things right, people won't be sure that you have done anything at all

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    What you have mentioned should be the first step in fault finding, the next thing that comes to mind is focus, if the cameras are out of focus you will get grainy pictures at night, hence the reason for focusing cameras using neutral density filters.

    Another thing;

    Are they dome cameras? If so, are the domes clean, if the domes are dirty they can reflect the IR beam, I've seen this before especially after rain. Condensation inside the domes cause problems similarly.

    Let us know what you find.

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    Yes George Lens is clean now.

    I opened one today and focus "looks" fixed.

    When i first put them up all was good.

    About 3 weeks ago i noticed that one camera was so foggy around the outer side of the picture at night that you could almost not see anything.

    Today i pulled the camera down and took the front glass off to have a look inside and clean it.

    Glass looked clean but i noticed that the glass had a black ring printed on it to seperate the leds from the camera lens.
    On closer inspection i noticed that the lens had a rubber sleeve around it and thought that it may be sitting too far back and letting some ir light reflect back into the lens so i pulled it forward before putting the glass cover back on.
    When screwing the cover on it pushed back the rubber sleeve stopping any ir light getting to the camera lens.

    Great now no foggy image just grainy looking.

    Very similar to this one;


    Will have a go at plugging one straight into the tv, then power supply, then cable run and post some pics tommorow if it doesnt rain.

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    I'm guessing the IR's are burning out by the looks of that camera. The problem with cheap IR cams, is the LED's used are of low grade and their life span is considerably shorter compared to high quality IR LED's. Ever wondered why IR Illuminators are so expensive?

    My money is on the LED's, noise on video is generally "hum" seen as vertical or horizontal lines, but grainy images come down to two things, signal strength and focus.

    Check your voltages at the PS and at the camera.

    Check that you have approx 1vp-p at the camera BNC out and at the end of the coax.

    Update. The IR LED's in your cameras have about a 6000 hour life, professional Illuminators are generally more than 20,000 hrs.

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    Thanks George.

    I just went outside and all the led's seem to be working.

    This is a pic from before i took the camera apart and moved the rubber ring more forward....pretty bad hey?


    This is tonight after moving the rubber ring upto the glass

    You can see the image now but its just grainy.

    The other camera is clearer but also has a little grain to it.


    Hmm starting to realise i should have fitted seperate ir lights to stop the glare and spread the light.

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    Ok had my play today.

    First changed power supplies to another....no diffrence.

    Moved the power supply directly to the camera....no diffrence

    Removed the coax from the eaves and ran it straight to the camera away from any 240 wiring.....no diffrence.

    Removed camera and connected it straight into the tv with short direct wiring....no diffrence.

    So i pulled the damm thing apart.

    This is the camera


    Removed the cover, here you can see the black circle on the cover and a rubber sleeve over the lens. If you get a gap between the black circle on the cover and the sleeve ir light gets in and blurs the image.

    Here i removed the rubber sleeve to get the led board out.
    Note that the sleeve was trimmed by hand with a knife to fit around the led's.
    Hmmm made in china crap.


    Another cylinder to be unscrewed to get the camera with boards out.

    Bingo, found the focus adjustment, it was locked by the shiney screw. Once undone i could rotate the lens in and out.


    Darkened a room and started playing with the focus and found a improvement with only 1/8 of a turn.
    Reassemled making sure the rubber sleeve was pressed against glass cover to stop any ir light leaking into the camera.
    At least a 50% improvement with less graining showing on screen.
    The remaining graining i put down to a cheap, crap camera.

    Thanks George and best4less, focus did the job.

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    Your the man good work
    When you do things right, people won't be sure that you have done anything at all

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    A little trick I found with those types of cameras is to use a TINY dab of conduit cement on the focus adjustment to lock it in place.

    Good to see you found the problem

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