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Night vision surveillance Answered

I made a surveillance system out of 2 cheap web cameras. It works perfect, but night is the problem. I need to make it possible to record during night. I can't buy some professional IR cameras right now, but I got new neighbor who makes problems, and he is the reason why I am doing this. I found in local shop some IR diodes "100pcs 5mm 940nm IR" which cost about 5€. Are they good for my needs? They have to cover about 5-6m outdoor. And can I use them for my cheap web cameras? Any suggestion is welcome, need your help, or soon my stuff around a house will disappear!



1 year ago

I did some experiments with the cheap webcams I had left.
Was mainly with the optics but anyway, here we go:
Before you buy in bulk and start a lot of soldering it would be advised to check if the webcam in question works with IR ;)
Take your TV remote as an example: It uses IR and if you place the diode towards the cam and press a button you should see a bright flash.
Seeing just a small dot or a slight glow means the cam has an IR filter.
Using bright enough IR LED's you might still see enough but removing the filter in this case will give far better picture brightness - at the expense of color quality in normal light.
Getting a cheao 0-lux camera module might be cheaper in the long run.


Reply 1 year ago

It does not blink. I can see it pretty good on this web camera


Reply 1 year ago

That is great news!
You are lucky and should have little to no problems illuminating the area with IR so the cam can record properly.
One hint though: Simply get an IR illuminator for cams ;)
They come in 12V and have I think 48 or 96 diodes build in.
LED's without a proper refelctor and lens depend on the angle of light they produce, so if you buy in bulk aim for those LED's with an angle of 10° or lower to get more distance.
Also make sure to use "invisible" LED's, last thing you want is having a big red glow coming from the LED's at night ;)


Reply 1 year ago

Thank You! IR illuminators are very cheap but it will take about 15-30 days to ship to my country, I am from Bosnia & Herzegovina. If You could help me with soldering and wiring the ones I was talking about, that would be great!


Reply 1 year ago

There really is not much to it, basically the same as for any other (colored) LED out there.
Last time I did something similar I could not be bothered with creating a circuit board, so I used a small sheet of acrylic plastic and a drill...
Long story short:
Printed a "degree wheel" of the right size and glued in onto the sheet.
(A dregee wheel has lots of rings and lines for every 5 or 10 degrees of a circle - great for making circular patterns ;) )
Drilled the holes where rings and lines cross in the diameter of the LED's, in my case 5mm.
Using this on another sheet of paper I transfered he holes into dots using a marker.
This paper template was then used to draw lines indicating how to wire the LED's.
LED's pushed into the holes, legs bend and then soldered together to get sets to match the resistors.
After that a drop of superglue next to each LED to hold it in place and then all tested.
Finally sealed with with aquarium silicone to make it waterproof.

In your case it would pay off to check each LED first and to sort them according to their electrical values.
Ok, let me explain:
To save on time, resistors and premature fails you want the LED's to be used in series to get to a certain overal voltage.
For example the LED's are labeled for 2.2V and 25mA.
If you want to use them with 12V you would need a of around 390Ohm with each of them - a lot of work and can become costly too.
But if you can combine 5 identical LED's in series you get 11V for them and still only one resistor, make it six and you need no resistor as the LED's now would need 13.2V for full brightness.
In return they thank you with a longer lifespan as they now operate just under max power - each LED gets 2V instead of 2.2V ;)
However this only works properly if the LED's for each string of six are really identical.
Since it will be next to impossible to check them for brigthness (really measured not just by eye) while checking the electrical values you can only use the later for comparison.
No clue if you have a lab power supply and good multimeter, if so let me know and I explain how to test them.

As an alternative if you don't have the means to electrically test them:
Connect a string of them in series to a variable power supply, ideally a lab power supply.
If you don't have one either go with what you have ;)
Last resort would be a fixed 12 or 24V supply, the higher the better to safe time.
Connect a lot of LED's series, for example:
On a 12V power supply at least 10.
Check with your cam how bright they are, add more until you only see a few of them light up very dim.
Replace the ones you can see in the cam and put them aside - mark them as "early" for example.
If none of replacements light up brigther then the rest in the string replace the lot - mark them as "test second".
Once you are through your bulk pack you should have a hand full of "early" LED's and lots and lots of "seconds".
Now do the same again but maybe one LED less in the string so you again see one or two LED's glowing brighter than the rest.
Replace those and mark them as "early 2".
Keep repeating until you are through your lot again.
Now you should have more "early 2's" than "early" ones.
If you repeat the test with the bulk that is left you should see that there is now very little difference in brightness to see in your cam.
In this case they are ready to sort out the problem of mounting them.
The two lots of early LED's are discarded for a big illuminator and you should only use the remaining lot of evenly sorted LED's.
You can however check these early lots again the same way and if even enough use them for a smaller illuminator that might still give the same brightness with less LED's.

Just keep in mind to use ne more LED in series than what is required to match your supply voltage ;)


1 year ago

You can to a quick rudimentary check to see if your cameras are sensitive to the IR by taking a television remote control and pointing at the camera and pushing the keys to see if the camera can see the flashing infrared light. This doesn’t necessarily mean that your cameras can see other wave lengths of IR but at least you know where they are somewhat sensitive or not.

You might want to look for something like this https://m.gearbest.com/ip-cameras/pp_677757.html?wid=21

Good Luck!