Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

IR illumination LEDs

Status
Not open for further replies.

computer

New Member
Hi,

For my webcam, I want infared illumination (to see in the dark)..

I have a 9v 200ma max power supply and I need some info and products suitable to do this.

I would like, if possible some product numbers from www.cpc.co.uk, www.farnell.co.uk or www.maplin.co.uk on some leds suitable for illuminating as large an area as possible with infrared light (the greeny type of effect).

If you can tell me the amount of LEDs I should get, then that would be useful, and also any resistors or wiring info I need.

It will also really need to shine through glass onto the garden, about 3-4m below the camera and illuminate it for me.

If I shine a remote controller's LED (while pressing a button) at my camera I get a white light coming out on the screen if that helps....

many thanks,
computer
 
computer,

I'm not convinced you can just illuminate an area with IR for a standard webcam! The reason you see a white light, is because of the nature of CCD. (charged-couple device) This is the part of the camera that actually 'sees'. You get the same effect with camcorders, digital cameras and some camera phones.

I think in order to actually illuminate a worthwhile area with IR, you would need so many, and they would have to be very powerful. Also you wont get that cool military style special forces green look either!

I'd say it is impractical to do it! Depending on your application your better off using a special night time cctv camera, or just turning the lights on!

But if you'd want to have a go, just search for IR LED on any of the sites you mentioned, order the biggest sort with the highest candella rating (mcd) you can find. Order as many as you can bear, and attempt to make a nice circular array with them. If you position this under your webcam, facing the same way, that will achieve the best effect possible. But I do think that you will be dissapointed with the result!
 
Most cameras are sensitive to IR, your one obviously is as you can see a remote control with it. Maplin sell a number of cameras with IR LED's built in, and even an IR light with 28 IR LED's - this is rated at 10m range and comes in an external housing, which makes it rather expensive though.

RS Components sell lots of different IR LED's, look for high output ones with the output angle you are looking for - stack them together, the more you use, and the more current you feed them (within their limitations) the greater the range you will get.
 
Just out of interest, for max sensitivity to IR, the cheaper 'CMOS' sensor based camera's are best, not the CCD types, they have a huge sensitivity peak around 800nm. I've messed with this stuff, if using 5mm IR-LEDS? you'll need a bunch of em, if you want any decent range. Much of the problem is the wavelength of the common IR-Leds, are mostly around the 900nm range, which is a bit outside the ideal for cameras.

My solution was to obtain some ICI Black Acrylic (perspex) although it 'Looks' black, its not. This material is a very deep red. I cut (nibbled) a disc (using a guilotine) to fit in a 6 volt lantern type torch, mainly for use with my big Russian Gen 2 Night Sight, it works well with that and CMOS cheapy cams ;) You can buy the 'Proper' filters for IR, but they tend to be mega-bucks, try the black perspex, for pennies, and use a small spotlamp/torch. note.. not the Diochroic types as they shunt the IR (heat) component out the back of the reflector.

Steve
 
Just finished an underwater camera project for the county rescue squad, I tried putting a ccd camera and ir illuminator behind a piece of tempered glass in an enclosure for physical protection..The problem we encounterd was a harsh reflection off the glass from the ir leds. It didn't rear it's ugly head untill we tried it in total darkness, luckily it wasn't under emergency conditions. I tried several approaches to get rid of the glare and nothing worked.. Even tried substituting clear lexan for the glass..Without the enclosure the range of the illuminator was approx 50 feet on land and 6 feet in mildly turbulent (river ) water..I imagine if you want to use the camera indoors looking out, the room will have to be in total darkness and the illuminator located outdoors ....
 
All CCDs are sensitive to IR, but some like the Sony Nightshots are significantly better.

But that's not what Nightshot's about. ALL color cameras have a tiny IR filter installed that blocks it. Why? Because IR appears as greenish blue, whereas the eye sees nothing, so the picture doesn't look true.

Nightshot mechanically swings the filter out of the way. You can often remove the filter from the camera, but it sometimes messes up the focus. They also reprocess the color out of the CCD to look even more green, I've no idea why.

Despite the filter, some IR illumination is possible since it's not a perfect cutoff. But you'll get 10x-20x better illumination without the filter.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top