Ask LH: How Can I Automate A Flash On My Security Camera?

Ask LH: How Can I Automate A Flash On My Security Camera?

Dear Lifehacker, I’ve set up a security camera that peers over the fence into the carport, taking & storing a picture every minute, as well as snapping a picture every time movement is detected in the area. During the day, it records us coming & going, as well as the occasional appearance by a postman or delivery person. A couple of days ago, one of our cars was opened and things were stolen, of no commercial value, but highly frustrating to have to replace.

The “every minute” picture did capture two shots of someone moving around in the area and opening the car door, but as it was just after 4am, the lighting was not exactly the best, and all we have is a dark general outline of the intruder. So here’s the question: Is there any technology that I could set up, that would activate a camera flash as the webcam fires?

As the webcam picture is immediately uploaded to my website, I would already have a picture of the bastard before he could destroy anything. The technology in use is a Windows XP PC with a USB webcam attached, sitting on a shelf just behind the fence, running Tincam for the regular pictures & Yawcam handling the motion detection, with Webcam Splitter providing the image to both applications. As the unit complex has been experiencing numerous break-ins lately, I am keen to capture the culprit on digital media if possible.

Caught In The Act

Dear CITA,

Your story immediately reminded me of a similar experience which my brother had a few years ago. Two of his (entirely indoor) cats escaped from the house and went missing, so he set up a bowl of food in the laundry, left the door open and set up a motion-sensor camera. Unsurprisingly, the greedier of the two cats was caught on camera coming in for a meal late at night, which then made it worth waiting up to catch the miscreant moggy. But since this happened in the wee small hours of the morning, how did he ensure that he got the shot?

His answer? “The camera that I used has an infra-red mode. Given how old/cheap it is/was, I’d be surprised if newer ones didn’t have better settings.”

That obviously isn’t a direct solution to your problem, but it does suggest that an alternative strategy might not be too difficult to come up with using a slight change in hardware. I’m sure that someone with electronics skills could build something with an Ardiuno that triggered the flash for motion sensor images within certain hours, though it could be a fiddly job. Anyone out there got a detailed plan, or another suggestion on how to solve the problem?



  • Just put up a sensor light from the hardware store with a decent bulb in it. It might reduce the unwanted visitors, but if you place the light near the webcam you might get a good face shot when they look at the light.

  • Either buy a infra-red camera, OR just buy an outside light with a sensor. Set the sensor to sensitive with a 5 minute timer. When the intruder walks over, he sets off the light (which is a security benefit itself) and allows the camera to take photos.

    Having a flash go off every minute is a waste of time, money and resources. Plus there’s no guarantee they will be perfectly synced.

  • I suggest IR too, but make sure you get an IR array that is powerful enough to light up your area. No good relying on a webcam’s IR array that is only good for lighting faces at a meter or two away. I think you can buy commercial IR kits that are used for wildlife photography. They light up an area a number of meters away, without spooking anything that is nearby.

    Might cost a bit, but it’s peace of mind. You could also build one if you’re that-way inclined.

  • If my neighbour set up a webcam in his driveway which flashed every sixty seconds all night, I would either tear it down or punch him in the nose within a week.

  • You go to the trouble of setting up a PC and webcam in your carport and then leave your car unlocked?

    I suspect that you don’t really want to protect your valuables, but actually just want to show off a photo of someone “caught in the act”.

    If you’re going to continue to leave the car unlocked, at least make sure the interior light comes on so you have some chance at a decent face shot.

    • RB what he actually said was “A couple of days ago, one of our cars was opened” not “Our car is left unlocked all night”. Opened to me reads as “broken in to”

    • Leaving your car unlocked is actually not a bad strategy.

      I live in an apartment complex with a ‘secure’ parking garage. A few months ago, a guy wearing a hooded jumper followed a car through the roller door, and proceeded to break into 8 cars. Despite getting some good footage on the security cameras and providing it to the police, he hasn’t been caught.

      The satnav, leatherman tool and spare change that he stole from my car was worth a few hundred dollars, but it cost me over $1,000 to replace the smashed driver’s door window, get it re-tinted, and repair the damage to the door and window surround.

      Immobilisers make modern cars harder to steal, and a locked door provides very little impediment to a thief in any case.

  • An infrared camera and lamp is the simplest solution.

    Otherwise you’re going to need a motion detector or some sort of ‘tripwire’ to trigger the flash.

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