Video Surveillance Cameras

Hey - it's amazing what a dob of matt black paint will do...

Crabtree. I agree. I just want to sustain the ability to record video at night.

Thanks,

Don

By definition, there is much less light to record at night. Is this some special application, Mildred?

Since black paint is only reversible with difficulty, how about using something like black tape (perhaps electricians tape). That's what I use on the warning lights of my vehicles when they don't pass inspection. Or perhaps try an audio signal. If it bothers your prey, use headphones.

Red is not the same as IR, needless to say. If the LED is red, it's not IR; and vice-versa. If the camera has both, then I think what you need is a piece of infra-red transmitting, but visual blocking, plastic, to block the red LED but allow the IR LED (or any available ambient light) to still provide the illumination you need.

Google it; maybe find something like this that suits your needs:
http://www.eplastics.com/Plexiglass_Acrylic_Sheet_Infrared_Transmitting

The high power IR LED apparently has a little spill over into the red end of the visible spectrum. You might just cover it up and get a separate illuminator.

http://www.amazon.com/Invisible-Infrared-Illuminator-Illumination-Surveillance/dp/B00ECGZ52Q

Traditional infrared cameras evidently use 850nm wave length light source so you can tell when they are working....cameras with slightly higher 940nm wave length are available for covert operation...

..."940nm infrared LEDs so that they can not be detected by the human eye in the dark. Unlike traditional infrared surveillance cameras, which use IR LEDs that operate at a 850 nano-meter frequency, the IR LEDs in these cameras operate at a 940nm frequency and DO NOT emit a red glow. "....

http://www.cctvcamerapros.com/940nm-Invisible-IR-Cameras-s/793.htm

Ref that quote - to be a little pedantic, nm is wavelength, not frequency. Freqency = c/wavelength.

The human eye response function (photopic response) effectively ends at 740 nm. Technically it ends at 780 nm, but at this extreme end of the spectrum the response is so weak that only an extremely intense light source would be detectable.

The HPBW spectral output of an 840 nm LED is only about 25 nm. Thus, similarly, the output is so weak at 775 nm that only a tremendously bright array of 840 nm LEDs would be detectable.

Furthermore, the scotopic (dim lighting) response of the human eye shifts toward the blue end of the spectrum, so in low light the eye has even less response beyond 700 nm.

I'm pretty sure that the red LED on cameras is exactly that - a red LED, not a IR LED. If an IR LED is on-board to provide low level illumination it is in addition to the red LED.

"the output is so weak at 775 nm that only a tremendously bright array of 840 nm LEDs would be detectable." possibly from something like an IR ILLUMINATOR.

I'm sure sooner or later SolarEagle will make a mistake. Today does not seem to be that day.

No, it would need to be solar intensity. Even your IR ILLUMINATOR would not be bright enough. But I'm sure SE appreciates your devotion.

"No, it would need to be solar intensity. Even your IR ILLUMINATOR would not be bright enough."

I have about 500 of them deployed around the country. I know what I am talking about.

Well, ok then. I'm an optics engineer and I'm basing my comments on the testing I've done on discrete 840 nm LEDs. I've tested a LOT of individual IR leds over the years and I've never detected any visible glow. My thought was that for IR illuminators some deep red LEDs were mixed in so that there would be a visual indicator when it was on. But your experience was apparently different.

I think the difference of opinion here is based on the light emitter vs the light produced....the light produced is not visible to the naked eye, but the bulbs do produce a glow....here's an 850nm array...now this is probably more visible than would be to the naked eye, because the camera may be more sensitive to the light...

I am a long time subscriber & contributor. Everytime I read-follow a discussion it is like a tutorial- just excellent. As a physical organic-analytical instrumental chemist, elec engineer & sensor-transducer instrument designer-maker, I have constant requirements for information, guidance, assistance- knowledge. This is the finest site on the web, in my opinion, for this purpose in a great many disciplines. Superb !

You should contribute, the larger the knowledge base we have, the more interesting and informative this site becomes...

I like to watch too. The side issues can get fun.

715-730 nm: Overt IR, produces a soft red glow -
815-850 nm: Semi-covert IR, produces a faint red glow just visible to the human eye -
940-950 nm: Covert IR, invisible to the human eye

http://www.honeywellvideo.com/documents/NightVisionSecurity.pdf

Thanks to everyone for the suggestions and links.

Don

Don

A simple solution is buy a parking camera kit. They use IR LEDs for night parking and work quite well. Cheap too.

FLIR cameras, expensive in hi resolution, but low resolution module's are available around $350, you might also check into military style 'starlight' viewers, I have a monocular unit that you could mount a camera to.

Sony makes a ultra-low light CATV cameras called "Sony Super HAD CCD" video modules. They are incorporated into all styles of security cameras. Here a pdf link about the module.

You can get them with or without IR blocking.

I wanted cameras that did not use IR illumination because I had them mounted in top of the windows at an angle inside. Th IR light did two things it lit up the window washing out any image. Also I wanted no tat-tail light that could be seen with a camera that someone could use to survey the place with. The way they mounted in the window you could not see them unless you walked up to and looked up to see them.

I have a several of lipstick style cameras for several years now they work good in very low light with a viewing angle around 160dregs. A couple are .01Lux and the others are .001Lux "starlight". With mine there can be a little washout when they switch from night (b&w) to day (color) mode does not take long though. Just every now and then. I've seen it in the recording as the sun comes up.

A little moon light gives enough light to see any movement in the back yard to the sheds "about 50-75ft". The ones I have in the front with the street lights its just like daylight except sodium tinted.

One Halloween a neighbor about 800ft down the road used some black-light bulbs in there porch lights. To the camera it looked like they had floodlights on until I looked to see what they were doing. The best I could see by eye was there was some people moving.

Hope this starts you in the direction looking for. Charles

The info provided by SolarEagle & metalSmiths was/is of such high quality & clarity, that I went back & re-examined some of the cameras & camera systems we had installed at a very major International Airport in a middle eastern location. I was project lead for the modernization & optimization project to bring this airport into the 21st century in terms of surveillance & security. We installed surveillance & security hardware & software, implemented package left behind, facial recog, license plate ID-recog, nano-technology based explosives detection (my own sensor-transducer design), blindingly fast search-retrieval-update-store-recall systems, enormous on-site data storage & completely educated & trained an IT staff to monitor, maintain & continually optimize the systems. To give you some idea of the sophistication- this aggregate of systems continually runs AI algorithms to feedback into the optimization methodology- (again, my design & execution). But- I made some mistakes in re: the camera specifications, & this discussion revealed them. Not huge ones, necessarily, but this discussion revealed them, educated me & obtained the agreement of the camera experts to whom I sent the info- this discussion caught what even they had missed/overlooked. Replacements- more capable hardware !!!-more intelligent software- have been ordered, from multiple vendors, & when FedEx delivers them they will be installed & stressed within 4 hours, & then optimized. Can there be anything better than information, remaining open to continual correction & education/re-education, and having access to discussions that serve the interests of accuracy, optimization & pushing technologies forward !!!! This is why I say this site is....superb- & terribly important. This discussion has made an entire international airport in a very difficult area of the world, that sees millions of travellers annually, safer.

Thanks to everyone for the information! It really is amazing the answers that come in; some answers to questions that I didn't think to ask.

Don

I don't think this is entirely off-topic, but I have this question:

If you illuminate an area with non-visible infrared, could this be detected by a perp using his cell phone camera?

I ask because of the ability of the cell phone camera to "see" the emitters on a TV remote.

Yes, those cheap 'security' camera's are ringed with infrared emitters.

Thanks. I was trying to figure out if I could check to see if the infrared was turned on before I snuck out of the house at night.

Yes, most digital cameras can see a portion of the UV/IR spectrum. _{Your mileage may very}. Most cameras have UV/IR blocking or cut filters to stop the light outside of the visible range. Its to help the visible spectrum from having bright halos and soft images. As the UV/IR focus is a little different from visible.

Although most low lux B/W securty type cameras do not have the blocking/cut filters. But It does not hurt to check spec. sheets as some do have them.

Another thing to spot hidden cameras using an IR light source inline with a camera looking for the glint from the sensor element of the hidden camera provided it's not hidden behind something ie:window. Some movie theaters use this method to find people recording/pirating the movie.

There a sub-culture of DLSR users who remove the internal filters for astrophotography and IR photography.

little off topic.

Also Sony sold Nightshot (NiteShot) 0 Lux Handicams. That could do an "X-Ray" effect to see through clothes. Users found that if an infrared filter was added to the camera and the camera was operated in daylight, the camera could sometimes view through clothing. This effect is most noticeable on dark synthetic fabrics. _{Might be} NSFW _{if scrollred too far down the page}. Example.

Just some thoughts I'd pass on. Charles