Wavelenght of IR-lights in CCTV's - Page 1
Forum section: electronics / projects

author: cs.dk
author_rank: Unknown
timestamp: December 29, 2019, 08:46:36 am
content: I'm planning to buy a couple of cameras to extend my UniFi setup - How ever, many reviews on the G3 cam notices the IR-light doesn't reach very long.Instead of buying the expensive G3 Pro or really expensive G4 cam, I thought it may be possible to make an "IR floodlight". Maybe build into to a standardhalogen floodlight housing.I've never designed a PCB before, but I think with some practice, it should be doable, and a way cheaper solution.Does anyone know the wavelenght of the IR light i standard cameras?

author: oPossum
author_rank: Super Contributor
timestamp: December 29, 2019, 08:52:41 am
content: Usually 840 or 850 nm.

author: cs.dk
author_rank: Unknown
timestamp: December 29, 2019, 09:04:15 am
content: Thank youLooks like 850 nm is the most popular. TME has 20 different models, only one single 840 nm.Need to figure out the viewing angle, and how many/how powerful they need to be to light up ~25m

author: Kleinstein
author_rank: Super Contributor
timestamp: December 29, 2019, 11:02:42 am
content: Usually it is 850 nm to 950 nm. The 850 nm LEDs may be just visible as dim red light, but can have better sensitivity with modern detectors. The possible visibility is as the spektrum extends to both sides. So a 850 nm LED will still emit a little at 800 nm and 750 nm.If in doubt one should test if 950 nm is still OK with the camera before ordering a larger number.Besides the sensor there can also be absorption in the lens starting at 950 nm.The limited range is usually just from geometry, as the brightness goes down as the distance square. So its independent of wavelength.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 29, 2019, 01:22:47 pm
content: Just look up "IR illuminator" on Amazon and there are a lot of ready made modules for that purpose. Based on reviews, the ones with a few high power LEDs seem to be more reliable than the ones with a cluster of 5mm LEDs.

author: cs.dk
author_rank: Unknown
timestamp: December 29, 2019, 03:48:20 pm
content: OK, got it.. No need going the PCB-design route. Must learn that some other time.Haven't though of searching amazon, ebay, etc.. At that price, I can't do anything my self.https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR9.TRC2.A0.H0.XIR+illuminator.TRS0&_nkw=IR+illuminator&_sacat=0

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 29, 2019, 05:52:16 pm
content: If you also search Ebay for cheap emitters you may still be competitive in price for build your own. The attached photo shows one that I came up with. It was worth it when combined with the learning producing in bringing a PWB mill back to life. Don't imagine miracles, as Kleinstein says it is a square law problem, going both ways, so actually range is something like 1/R^4.There are two huge advantages to a flood illuminator. One, it is often possible to place the flood downrange at locations of interest, eliminating one of the 1/R^2 factors. Second and vastly most important is that you will learn that these IR lights are quite visible to insects who fly around them as they do around visible lights. The insects attract spiders which build their webs near the floods. When the IR lights are co-located with the camera the reflections from the web strands capture the camera AGC and ruin visibility. Cleaning the webs is often needed on a weekly basis or even more often. So moving the light away from the camera eliminates the problem. If your system doesn't allow turning the built in lights off they can be masked off to stop them from attracting insects.

author: cs.dk
author_rank: Unknown
timestamp: December 30, 2019, 06:41:30 am
content: Thank you for replying.Sounds like a good idea to get a IR floodlight, instead of using the cameras onboard IR. Haven't thought of insects.