CCTV cams give different results

Store Forums Video Experimenter Bugs/Problems CCTV cams give different results

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    Put my first Video Experimenter into use yesterday! The first of at least six. There was a display problem but it was usable. After looking at the backgrounds of a couple cameras it was decided that the overlay on a different camera would be better because of the darkness of the background would make the overlay more visible.
    When the cameras were switched the overlay was perfect! I do have pictures of the difference but when I try to attach files using the upload attachment at the bottom of the message area here I get; “Sorry, the board attachment qouta has been reached”. Made them with Skitch so neither one is larger than 29k.
    So to move on, something about these CCTV cameras is different from what we are used to.
    They can be PAL or NTSC and it isn’t a setting. Here is an example of some of the specs;

    Image sensor: 1/3″ interline transfer type color CCD (Sony)
    Effective pixels: 768H x 494V (380k pixels)
    Scanning system: 525 lines, 2:1 interlace
    Scanning frequency: 15.734KHz (H), 59.94Hz (V)
    Resolution: 540TVL

    Unfortunately I don’t know the specs of either of the two cameras being referred to. Finding out would mean climbing the pole and taking a good look to be able to reference the web about that particular camera. Not really a problem if it helps. Looking at some of the other cams purchased, less info is available “Camera has resolution of 420 TV lines”.

    If there are any suggestions about camera info or how to post pictures please let me know.


    Glad you are having success with a different camera. It does seem strange that the camera you references can output PAL or NTSC, yet there’s no switch to change the mode. Have you tried using PAL instead of NTSC in the overlay code? Just change NTSC to PAL in the TVout initialization.

    I have changed the forum parameters to allow attachments, so you can try again. You are also free to email images to me.

    I have devised a way to make a dark gray background behind text (as long as the dark gray block spans the entire line). If this would help with your contrast issues, let me know. It requires a 74HC4066 analog switch chip (about 35 cents) and some code modifications. I will be blogging about this soon but can get you started if you are interested.

    • This reply was modified 5 years, 6 months ago by Michael.
    • This reply was modified 2 years, 10 months ago by Michael.


    Here are the pictures. VE board gone till another comes. Will test PAL settings.


    Maybe I should explain the pictures a little better. the larger sized one comes from a handheld shot with iphone. So there is slight movement you can see from the CH04 which is generated by the DVR. The DVR is also generating the very very bottom line that says;

    2011-07-09 12:38:33 M2

    Everything else is from the VE including the box of snow at the bottom.

    This is basically what was happening to the overlay demo when I left a message last week.
    The snowy box and a doubling of what is being printed to the screen.

    The second smaller picture is a screen grab from slingbox today since I didn’t take a picture of a monitor like the handheld shot. The 20 in the right corner and the accuracy first is what the VE is generating. The CH01 is from the DVR.



    Ok, have hooked up a new board with the same results.
    This is using the same sketch that the pictures uploaded in previous message show.
    Tried with the tv.begin(PAL, W, H).
    It is better but not right. The bottom box of snow is all gone. The accuracy first is shifted all the way to the right where the arm of the t in first is just off screen right. The “accuracy” is flickering on it’s same row.
    The numbers are on the right edge with a bit of the second number cut off by screen right.
    The numbers also flicker but show five digit number as a flicker.
    I mentioned before that the CCTV cams are PAL compatible but the reference to my knowledge at this point is unknown. Can’t remember the details of the reference. I can say that with the sketch that I am referring to in the NTSC version, there is a TV that will play it perfectly. So there are two situations I can reproduce.
    1.Cam in the video that plays like uploaded pictures. Same cam setup will play on particular TV.
    = same cam needs particular output device to work correctly
    2.Then the actual situation uploaded in the pictures. Same output different results based on input
    = different cams needed to make output devices work correctly

    The second option worked on every output device in the store. Tube BW monitor, computer monitor driven by video to VGA box, 7 inch 12v headrest LCD monitor. I would say that signal would play on anything.

    I have at least five different resolution CCTV cams. Going to see if any others work in NTSC or PAL mode. The cam that was used for the uploaded picture is one I didn’t install. It is outside on a pole so I have no idea about the resolution or make.
    Any guesses as to what resolution will work? Anyone with any ideas?


    Happy to report that the cameras that that have a problem are Q-See cameras. Q-See is a brand name. At least in the group of CCTV cameras that were available for me to test the cams from Q-See are the ones that won’t sync perfectly.
    The rest worked in both NTSC and PAL with the only difference being the exact placement of the overlay.
    These Nootropic VE boards are awesome! They are easy to use in the world of Arduino.
    So one last question, is there anything that will print rows of text to screen as easy as the Nootropic VE board?
    I don’t think so. It is also a great programming and debugging tool. Printing to screen is a snap.


    I’m glad to hear you’ve figured out the root of the problem. Great work, and thanks for posting all the information!

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