how does lux work for security cameras?
479824
I guess 'moonlight' might be nice for security... tech explaination follows:\n\nThe lux (symbol: lx) is the SI unit of illuminance. It is used in photometry as a measure of the perceived intensity of light. In English, "lux" is used in both singular and plural[1].\nOne lux is equal to one lumen per square metre.\nIlluminance Abbr.   Example\n0.00005 lux or 50 µlx  Starlight\n           1 lux    Moonlight\n400 lux  A brightly lit office\n400 lux  Sunrise or sunset on a clear day.\n1000 lux or 1 klx  Typical TV studio lighting\n1000 lux or 1 klx  Approximate minimum level required to reset the biological clock in humans\n32000 lux or 32 klx  Sunlight on an average day (min.)\n100000 lux or 100 klx  Sunlight on an average day (max.)\n\nLux versus lumen\n\nThe difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. 1000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1000 lux. The same 1000 lumens, spread out over ten square metres, produces a dimmer illuminance of only 100 lux.\nAchieving an illuminance of 500 lux might be possible in a home kitchen with a single fluorescent light fixture with an output of 12000 lumens. To light a factory floor with dozens of times the area of the kitchen would require dozens of such fixtures. Thus, lighting a larger area with the same number of lux requires a larger number of lumens.\n\nRelationship between illuminance and power\n\nIlluminance is not a direct measure of the energy of light, but rather of the illumination it provides as perceived by the human eye. Thus, the conversion factor varies with the wavelength composition or color temperature of light. At 555 nm, the middle of the visible spectrum, one lux is equal to 1.46 mW/m².
948741
How light guns work\n\nThe "light gun" is so named because it uses light as its method of detecting where on screen you are targeting. The name leads one to believe that the gun itself emits a beam of light, but in fact most light guns actually receive light through a photoreceptor diode in the gun barrel. [Re].\n\nThere are two versions of this technique that are commonly used, but the concept is the same: when the trigger of the gun is pulled, the screen is blanked out to black, and the diode begins reception. All or part of the screen is painted white in a way that allows the computer to judge where the gun is pointing, based on when the diode detects light. The user of the light gun notices little or nothing, because the period in which the screen is blank is usually only a fraction of a second.\n\nSequential targets\n\nThe first detection method, used by the Zapper, involves drawing each target sequentially in white light after the screen blacks out. The computer knows that if the diode detects light as it is drawing a square (or after the screen refreshes), that is the target the gun is pointed at. Essentially, the diode tells the computer whether or not you hit something, and for n objects, the sequence of the drawing of the targets tell the computer which target you hit after 1 + ceil(log2(n)) refreshes (one refresh to determine if any target at all was hit and ceil(log2(n)) to do a binary search for the object that was hit).\n\nAn interesting side effect of this is that on poorly designed games, often a player can point the gun at a light bulb, pull the trigger and hit the first target every time. Better games account for this by detecting if all targets appear to match - that would mean cheating.\n\nCathode ray timing\n\nThe second method, used by the Super Nintendo Entertainment System's Super Scope and computer light pens is more elaborate but more accurate.\n\nThe trick to this method lies in the nature of the cathode ray tube inside the video monitor. (CRTs were the only affordable TV monitors in the late 1980s and early 1990s, when this method was popularized.) The screen is drawn by a scanning electron beam that travels across the screen starting at the top until it hits the end, and then moves down to update the next line. This is done repeatedly until the entire screen is drawn, and appears instantaneous to the human eye as it is done very quickly.\n\nWhen the player pulls the trigger, the computer (often assisted by the display circuitry) times how long it takes the electron beam to excite the phosphor at the location the gun is pointed at. It then calculates the targeted position based on the monitor's horizontal refresh rate (the fixed amount of time it takes the beam to get from the left to right side of the screen). Either the computer provides a time base for the horizontal refresh rate through the controller's connector (as in the Super Scope), or the gun reads the composite video signal through a T-connector on the A/V cable (as in the GunCon 2). Once the computer knows where the gun is pointed, it can tell through collision detection if it coincides with the target or not.\n\nMany guns of this type (including the Super Scope) ignore red light, as red phosphors have a much slower rate of decay than green or blue phosphors. So some (but not all) games brighten the entire screen for a frame in order to get a more reliable fix on the position.\n\nDisplay timing is useless with plasma, LCD, and DLP, which refresh all pixels at the same time.\n\nCombining the methods\n\nSome light guns designed for sequential targeting are not timed precisely enough to get an (X, Y) reading against the video signal, but they can use a combination of the two methods. First the screen is brightened and the response time is measured as in cathode ray timing, but the computer measures only which scanline was hit and not which horizontal pixel was hit. This does not need nearly as fast a timer that pure ca
185051
They tend to be either vibrating models (vibrating pillows) or strobe.  Like the doorbell/telephone, strobe lights work very well in this application.
488916
No different than the use of traditional cameras.\n\nGenerally, nobody really cares unless you are working in an area that may contain classified materials.\n\nIn fact the Army is issuing digital cameras to squads in Iraq.  This way a soldier in the field can take a picture of something and transmit that picture electronically to the people who either need the information (or can tell him what he is looking at).
1099256
Developed by Agilent Technologies and introduced to the world in late 1999, the optical mouse actually uses a tiny camera to take 1,500 pictures every second. Able to work on almost any surface, the mouse has a small, red light-emitting diode (LED) that bounces light off that surface onto a complimentary metal-oxide semiconductor (CMOS) sensor. The CMOS sensor sends each image to a digital signal processor (DSP) for analysis. The DSP, operating at 18 MIPS (million instructions per second), is able to detect patterns in the images and see how those patterns have moved since the previous image. Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the computer. The computer moves the cursor on the screen based on the coordinates received from the mouse. This happens hundreds of times each second, making the cursor appear to move very smoothly.
1140780
Use the night mode on your camera. Or rent a light kit.
168125
If it came with software, then you could probably change the settings from there.  Or, you could just increase the light in your room where the webcam is.
189372
download the windows xp powertoy called "timershot" from the microsoft website free of charge you can program it to take pictures while recording with your webcam and it detects your camera automatically.
1013159
Have you a Philips camera connected to your pc?... I believe its part of the software that comes with the camera. Are you running under a 'Limited User' account, as doing this can stop programs from accessing 'sensitive' areas of your system... if so, find traymin200.exe and right click it, choose 'run as' and enter the name and password of your admin. account, or log on as an Administrator and see if it runs... if this works you can configure your system to run this file with elevated privilages---but before we try that, just see if it works
502209
It depends on what it is used for. \n\n"Non-covert" video surveillance cameras in public places is mainly a crime deterrent if suspects are aware that the area is equipped with surveillance cameras. They also present strong capabilities to identify and effectively prosecute crimanal acts AFTER they occur. The vast majority of "non-covert" video surveillance in public places is not made to stop crimes as they happen, but to record the evidence and suspects involved for prosecution afterwards.\n\nTo the majority of the general public, video surveillance presents a false sense of security. Surveillance cameras will not jump from the wall and help you fight off a mugger. A human response is still needed and when hundreds of surveillance cameras are being monitored by just a handful of people, the chances are slim that assistance will be immediate. However, the video evidence is key in identification of the suspect and eventual prosecution.\n\nThe most effective tool in the goverment's new "Federal Public Surveillance Act" is the use of Biometrics. The ability to identify anyone within a goverment database through Biometrics is a HUGE advancement in apprehending not only wanted criminals, but known terrorists as well. A basic form of facial recognition Biometrics has been used in casinos for many years. A specially designed software is able to take a surveillance shot of person's face and "map" it's individual features. The suspect can then be identified anywhere in the world where the software is active through surveillance cameras. The goverment has advanced from facial recognition systems that can be fooled with disguises, and have progressed to Thermo-Biometrics that can map anyone's face by the specific heat patterns that is generated in different areas of the face. The database will be shared throughout the United States as well as several other countries overseas. The capabilities of this system will be a HUGE advancement on the war against terrorists.
860907
So there you go!  Spag who I guess says he is a cop warns you that if you have the audacity to do the right thing and inform him you are recording he WILL punish you with a ticket!  Thanks for the warning copper but I have never told cops I record them and I record them EVERY time I am confronted by one.  Neat thing about digital cameras nowadays is they can be used to record video so if you carry it in your pocket all you have to do is turn it on and while there won't be a picture the sound quality is quite good.
729250
The UK is home to around 20% of all the world's overt CCTV cameras (roughly four million, or one for every fourteen or fifteen people).  However these figures don't consider covert cameras, such as those mounted in police patrol cars.  Nor do they acknowledge public webcams or domestic CCTV.\n\nFor what it's worth the majority of these systems are passively monitored until needed, but with year-by-year advances in pattern recognition technology (read: AI) there'll be a greater degree of automated active monitoring.\n\nAnd with respect to your talk of black boxes in cars...  It's just a matter of time.  The current trend toward more and more toll roads will require some kind of convergent monitoring, and little black boxes with GPS capability will go a long way toward allowing that.  (Red Ken Livingstone would just LOVE one of those on YOUR car, whether you live in London or otherwise.)\n\nFurthermore, the capacity of CCTV to "catch" criminals is completely overshadowed by the courts inability to effectively prosecute them.  Any suggestion that CCTV makes our streets safer is a myth busted wide open by independant, authorative observation (that's you and me).\n\n(Do you really believe the streets are safer to walk these days?  I don't.  I can see it with my own eyes, and I don't have to watch the broadcast news or read the papers every single day to appreciate it.  CCTV will NOT protect you, me, our friends or our families.  It does not deter.  At best it affords a visual record of past events, and at worse it offers a false sense of security.)\n\nAs for this Government's fascination with ID cards and greater immigration and anti-terrorism controls, any monitoring technology that may benefit that end will definitely be employed for tasks beyond its original purpose; this is the norm.  At great cost to the taxpayer, and with a contrasting threat to civil liberties.  (Read: we're paying toward an Orwellian future.)\n\nThere's a pattern forming here, and never before has the word 'monitoring' taken on such an ominous undertone.\n\nOh, and that old classic line of "If you've got nothing to hide then you've nothing to fear" is a fallacy.  We, all of us, strive to be private citizens.  We, all of us, have something to hide, whether it's our sexual preference, secret crush, betting addiction, bank ballance or exam results.\n\nThe plain and simple truth of it is that we, all of us, have something to fear from a Big Brother state.  Oppression is born of an ideal, yet matures through ignorance and denial.  But even though history is a damn fine teacher we so easily forget the past.
308053
It takes several steps for a digital camera to take a picture. Here's a review of what happens in a CCD camera, from beginning to end: \nYou aim the camera at the subject and adjust the optical zoom to get closer or farther away. \n\nYou press lightly on the shutter release. \n\nThe camera automatically focuses on the subject and takes a reading of the available light. \n\nThe camera sets the aperture and shutter speed for optimal exposure. \n\nYou press the shutter release all the way. \n\nThe camera resets the CCD and exposes it to the light, building up an electrical charge, until the shutter closes. \n\nThe ADC measures the charge and creates a digital signal that represents the values of the charge at each pixel. \n\nA processor interpolates the data from the different pixels to create natural color. On many cameras, it is possible to see the output on the LCD at this stage. \n\nA processor may perform a preset level of compression on the data. \n\nThe information is stored in some form of memory device (probably a Flash memory card). \n\n\n\n\nmore Info refer\nhttp://electronics.howstuffworks.com/digital-camera.htm
148911
there is a red light that flashes on for what ever  camera they are to look at
249893
You have to go into set defaults and set you webcam up in there to get it to work. You most likely will have to turn your computer off and let it boot back up before it will allow the changes.
247497
see film scanners:\nhttp://www.bhphotovideo.com/bnh/controller/home?O=breadCrumb&A=search&Q=&ci=1151
626755
passive infrared detectors, solid-state cont actors, ultrasonic devices, and photosensitive controls at their disposal\n\n\n\nManual or automatic dimming equipment, which can respond to many inputs, allows the illumination of a space to be set at any desired level. The semiconductor used in a dimmer circuit is called a triac. The triac provides phase control, meaning that it regulates the current to the lighting load by only conducing during a selected part of the AC power cycle.\n\nIncandescent dimming devices include wall box-type units rated as high as 2,000W that can fit in a single-gang electrical device box. Some models allow dimming from two or more locations, which previously required a remotely controlled dimmer module.\n\n\n\nfor any further clarification, you can mail me