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  • Security System, Building an expensive camera lens, cheap.

    I have recently installed a video surveillance system. We have been having some instances of people driving up to the top of the hill and parking in the cul-de-sac at the end of the road. One person, young male, pretending to read a book when approached. They are checking out how much activity there is in the area and if they will be noticed. This is, according to the police, the latest technique the B&E artists are using. They are moving out to the rural areas because it's becoming too difficult in town. Sigh.

    I do have protection starting with Beardog and followed by Spalding and ending with Ruger, Enfield and Winchester etc but I would prefer they don't try me. To that end I have put up a nice 2 camera wireless video system. One overlooks the cul-de-sac and the other is focused on our main driveway and my shop area. It lets me know when someone is checking out our hill. All I need to do is flip on my 2500 watts of halogen yard lights that they can see through the trees and then they leave.

    The lens is a wide angle add-lens which I made from scrap photocopier lens elements. It's a two element lens using a double concave coated objective and a multicoated plano-convex secondary. All parts of the body of the lens are turned on my SB9 from ordinary black plastic water pipe.

    I like making things on the lathe from plastic pipe as it is cheap and turns very nicely. You have to be a bit creative when it comes to work holding but a selection of wooden plugs helps a lot. Also, if you do crash the part it just flies out of the chuck and at the worst you start over with a new piece.

    Plate 1 shows the lens.



    In the next plate you can see the camera on the left in the as supplied configuration. These are pretty nice units that I bought on sale from Radio Shack (called "The Source" here). They are all metal, not one piece of plastic anywhere, not even the receiver case. The cameras are weather tight and the range is about 300 feet. I have stepped that up a lot by using the receiver at the focus of a small satellite dish in the attic of my garage shop. That also helps overcome interference since these run on 2.4 ghz along with everything else in the world. They work fine out here but wouldn't likely be acceptable in a built up area because of RFI. They still need a power source but that is easy and cheap to run compared to 300 feet of low loss video cable.

    The pic below on the left is what it looks like on the el-cheapo 13" color TV I bought for a realtime monitor. On the right is how it looks with the wide angle add lens. It isn't extreme and so doesn't introduce much distortion but does nicely increase the observable area.



    In the next plate on the upper left is a view of the cul-de-sac from the other camera.

    On the right I also have the image being sent to a new single purpose web server I set up that serves a new image on the web every 30 seconds. That can be seen on any web browser including around the property and house on my wireless Palm TX handheld. In fact, I can check up on things from anywhere in the world that I have wireless access. I am not releasing the address as that would kill my servers with the load.

    The lens is a universal add-lens since it produces a virtual image at infinity. You can hold it up to your eye and see the same effect or stick it in front of a digital camera. The bottom two pics are what it looks like when held in front of the lens on my Nikon 4300, wide angle on the right.



    The optics are simple, two standard lens elements with an air gap. The double concave objective receives light from a wide angle and without inverting it spreads it over the area of the convex secondary. The secondary refocuses the rays to the angle that the camera's normal lens is able to encompass. The add lens is adjustable for spacing between the elements as this controls the apparent distance of the virtual image.

    The below figure shows the approximate optical path.



    I will be busy for the next few hours but if anyone has questions about the lens or security system I will try to answer them later.
    Last edited by Evan; 09-10-2007, 03:33 PM.
    Free software for calculating bolt circles and similar: Click Here

  • #2
    Hi..

    You left out pci video4 board ($25 off ebay), Linux (free), motion-detection software (free) and XAWTV (free)... It snaps a picture everytime something moves. OR a video.

    all off sourceforge.org and other places.

    Why make a lens? I am confused.. aren't they cheap? are you after some ultra resolution?

    I have a $85 microscope camera, a $20 Northerntool telescope that plug together to allow 200 yard viewing. I got some excellet shots of the meth dealers I had next door in the obnoxious rental trailer.. As soon as I pointed out the camera pointing to my driveway, thier door, they moved off.

    So, old mailboxes, shot glasses (looks like a lens), and a blinking led would work almost as good as a camera. A local store put up large signs under all thier cameras, camera 1,2 etc.. thefts went way down. I have considered it.
    Excuse me, I farted.

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    • #3
      I use nothing but free software. Sourceforge is the first place I look.

      A wide angle add lens to fit that exact camera probably doesn't exist. If it does I am certain it isn't cheap. Note that this is an "add lens". It is added to the lens already in place. This is for cameras that don't have interchangeable lenses that will not work in this case. An add lens is usually designed to produce a virtual image at infinity which ensures it will work with any camera it fits.
      Free software for calculating bolt circles and similar: Click Here

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      • #4
        One of the more effective ways of "noticing" is to just happen to be out with the shotgun when you "notice" the guy parked.

        A nice friendly question like "howdy, boy, you lost?" while you have the shotgun over your arm is very discouraging to loafers.

        Questions about "squealing like a pig" are optional if there are a couple of you.........

        Any decently competent thief will clean you out and take the camera et al with him.
        1601

        Keep eye on ball.
        Hashim Khan

        Comment


        • #5
          Originally posted by J Tiers
          Any decently competent thief will clean you out and take the camera et al with him.
          Ah, but will a thief also be competent enough to find the server address and delete those last few pics saved on the server showing him reaching up to get that camera? If he really is that good he ought to be breaking into a much more high class place.
          .
          "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

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          • #6
            Any decently competent thief will clean you out and take the camera et al with him.
            Not while I'm home which is nearly all the time. I don't sleep much either, 2 to 3 hours per night.

            Also, he isn't going to find the camera looking out on the road. My wife knew where it is because I showed it to her but when she went for a walk on the road she couldn't find it. It looks like a stub of a tree branch and is painted olive drab. It's also 15 feet up a tree.

            I have an advantage in that my property can only be approached from one place, up the driveway. The rest of my frontage is protected by a 30 to 40 foot deep and steep ravine filled with dense trees and brush as well as brambles. There is no access at all to the other sides of the property except by hiking overland.
            Free software for calculating bolt circles and similar: Click Here

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            • #7
              Originally posted by TGTool
              Ah, but will a thief also be competent enough to find the server address and delete those last few pics saved on the server showing him reaching up to get that camera? If he really is that good he ought to be breaking into a much more high class place.
              I have heard that it is considered bad form among competent thieves to simper sweetly as you stare into the camera with your uncovered face......
              1601

              Keep eye on ball.
              Hashim Khan

              Comment


              • #8
                Originally posted by J Tiers
                One of the more effective ways of "noticing" is to just happen to be out with the shotgun when you "notice" the guy parked.

                A nice friendly question like "howdy, boy, you lost?" while you have the shotgun over your arm is very discouraging to loafers.

                Questions about "squealing like a pig" are optional if there are a couple of you.........

                Any decently competent thief will clean you out and take the camera et al with him.
                I would recommend not showing the guns.

                Knowing that you have guns tells the bad guys that you have something worth stealing...the guns.

                Good thieves are not deterred by firepower...they will put them on their to-steal list.

                The real key is not to flaunt your wealth.

                In regards to a HSM theme, the fewer people who know you have valuable tools the better.

                TMT

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                • #9
                  Excellent posting Evan.

                  I would be interested in hearing any details you wish to offer of the project.

                  TMT

                  Comment


                  • #10
                    Originally posted by Evan
                    The lens is a wide angle add-lens which I made from scrap photocopier lens elements. It's a two element lens using a double concave coated objective and a multicoated plano-convex secondary.
                    It appears that you have fashioned a wide-angle converter lens, such as this one which fits your camera: http://www.amazon.com/Nikon-Wide-Ang.../dp/B000052187 These converters are usually quite short. I'm wondering why you have such a relatively long barrel. Was this dictated by the surplus lens elements available?
                    Last edited by aostling; 09-11-2007, 01:47 AM.
                    Allan Ostling

                    Phoenix, Arizona

                    Comment


                    • #11
                      Originally posted by Too_Many_Tools
                      I would recommend not showing the guns.

                      Knowing that you have guns tells the bad guys that you have something worth stealing...the guns.

                      Good thieves are not deterred by firepower...they will put them on their to-steal list.
                      Take this to heart - 20/20 did a special a bunch of years ago, with a former professional burgler. He pointed out a bunch of things -
                      1)The three things that burglers are looking for are guns, prescription drugs, and jewelry(all three have street value). I imagine expensive portable electronics like laptops and Ipods also go into the mix.
                      2)the things they fear most are armed homeowners and dogs, in that order.
                      3)Those security systems aren't much of a deterrent, but they do put them to the clock - most claim a 3-5 minute response time. Most burglers are in and out in less than 2. Their demo was completed in 45 seconds.
                      4)Because time is not their friends, anything to slow them down, like front doors that lock with a key from the inside(forcing them to go back the way they came), or casement windows surrounded by rosebushes. a keypad to activate the garage door opener, instead of just a button..
                      5)Most burglers will make a beeline for the masterbedroom - this is where the jewelry is, this is where the drugs probably are(master bath), and this is where the guns are likely to be(in the master bedroom closet), so for your own sake, don't store your wifes good jewely or your vintage Parker there!
                      Camera's - one of the best places to put a camera is in your garage, because they'll tend to open it and pull their getaway vehicle in while they loot the house. Often you can catch the license plate.
                      6)Don't go nuts on securing the front door - burglers rarely come in that way. They're most common avenue of entry is either a basement casement window, or a sliding glass door, because neither can be seen from the street.
                      EGO partum , proinde EGO sum

                      Comment


                      • #12
                        Allan,

                        It's actually the same optical principle as this one:

                        http://www.amazon.com/gp/product/B00...d_i=B000052187

                        Yes, the length is dictated by the available lenses. But more important is that the Nikon 4300 is capable of focusing to points other than infinity so the converter needn't be configured to provide an infinity focus virtual image. If I stacked the elements so that they were nearly touching then it would produce a focal point somewhat short of infinity, not a problem for an autofocus camera. The security camera is fixed focus at infinity and that requires the converter to do the same.
                        Free software for calculating bolt circles and similar: Click Here

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                        • #13
                          Camera's - one of the best places to put a camera is in your garage, because they'll tend to open it and pull their getaway vehicle in while they loot the house.
                          Ha ha ha ha ha ha......
                          Free software for calculating bolt circles and similar: Click Here

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                          • #14
                            Things work a little differently here. Note that I mean here, not someplace like Vancouver.


                            1)The three things that burglers are looking for are guns, prescription drugs, and jewelry(all three have street value). I imagine expensive portable electronics like laptops and Ipods also go into the mix.

                            Here booze is high on the list. Everyone has guns including the perps. Nobody ever uses them though. Also popular are snowmobiles and cars.

                            2)the things they fear most are armed homeowners and dogs, in that order.

                            Reverse that order here.


                            3)Those security systems aren't much of a deterrent, but they do put them to the clock - most claim a 3-5 minute response time.
                            Most burglers are in and out in less than 2. Their demo was completed in 45 seconds.

                            The response time of the police here to a B&E ranges from whenever they finish lunch plus 1 hour to the next day, if they bother at all. I am not exaggerating at all, it isn't a priority and many of the surrounding communities have no resident policing.


                            4)Because time is not their friends, anything to slow them down, like front doors that lock with a key from the inside(forcing them to go back the way they came), or casement windows surrounded by rosebushes. a keypad to activate the garage door opener, instead of just a button..

                            Physical security is useless here. If somebody wants to get into my house they will either drive or chainsaw through the wall. Nobody will notice. I don't bother to secure the house and usually leave it unlocked. Less damage that way.

                            5)Most burglers will make a beeline for the masterbedroom - this is where the jewelry is, this is where the drugs probably are(master bath), and this is where the guns are likely to be(in the master bedroom closet), so for your own sake, don't store your wifes good jewely or your vintage Parker there!

                            Camera's - one of the best places to put a camera is in your garage, because they'll tend to open it and pull their getaway vehicle in while they loot the house. Often you can catch the license plate.

                            See previous post.

                            6)Don't go nuts on securing the front door - burglers rarely come in that way. They're most common avenue of entry is either a basement casement window, or a sliding glass door, because neither can be seen from the street.

                            See item 4. None of my house or outbuildings can be seen from the street. This is a rural area. The urban rules do not apply. The best deterrent is to put them on notice that you know they are up to something in your area. That is the point of my security system. The very first night after I installed it we had a "parker" in the cul-de-sac. He took off as soon as the lights were turned on. The security system alerts us to their presence. Nobody on the hill here can see the cul-de-sac from their house.
                            Free software for calculating bolt circles and similar: Click Here

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                            • #15
                              Originally posted by Too_Many_Tools
                              I would recommend not showing the guns.

                              Knowing that you have guns tells the bad guys that you have something worth stealing...the guns.

                              Good thieves are not deterred by firepower...they will put them on their to-steal list.

                              The real key is not to flaunt your wealth.

                              In regards to a HSM theme, the fewer people who know you have valuable tools the better.

                              TMT
                              Anyone living out there has guns.... except wild tree-huggers. That's sorta silly.

                              They may not know exactly where you live anyway, you walked up out of the woods, and a quick response is quite discouraging.

                              If I WANTED to discover what you have and where it is, I could do that. And then steal it if I so desired. There is ALWAYS a way. Like assassins.... Study the ways of the dictator, and eventually you see how to get him.

                              The key is that criminals, at least ones who are planning oriented, which includes these, like "easy". If it looks hard, they move on.

                              My wife's aunt locked herself out of her house.

                              I was inside in 1 minute, through the sliding door, which was secured from outside with one screw. Took that long because I didn't want to do damage......
                              Last edited by J Tiers; 09-11-2007, 10:26 AM.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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