IR question/confusion

[latenightrob 0]

I read a lot regarding bugs and IR cameras, so I got two cameras without the IR (color bullet)

At night of course the picture is barely there so I built a 36 IR led (940nm) and it actually does nothing, if I point the leds at the camera it does pick them up but actually helping the camera at night in the FOV it does nothing.

After reading some more threads I read that not all cameras pick up the 940nm?

So, now I am wondering if anyone could point me in the right direction to really understand what IR is all about.

Keep in mind I am doing the security camera thing at home and more or less as a hobby, I have had no problems, but I have always wanted to do this, but not for a ton of $. It is a pc based NV5000

thanks

rob

[cctv_down_under 0]

try to understand that light has a pretty broad spectrum...although we cant see most IR light some cameras can...but if we didnt sheild the camera from IR light then the colours and response of the camera would be affected...the Ir light isnt just there when you have a lamp...sun and other things give of IR.

 

Each colour camera therefore has a filter to block IR light coming into the camera, this is why with a true day/night camera the filter is removed when low light levels are detected to allow IR light to pass through to the sensor.

 

Cheap colour bullets will have not have a removable filter and therefore they block the IR light

[latenightrob 0]

thanks, that clears things up, I wasn't thinking about other things creating the IR light. Now, I am in a pickle, I need to replace my cameras.

[cctv_down_under 0]

Cost effectively Blanck an white cameras will be the best replacement, they dont have the filter...but then it makes it hard to say "he was wearing a red shirt".

 

True day night cams use the mechanical filter and obviously with moving parts its much better to buy quality

[latenightrob 0]

I think B/W camera may be the right way for me. the true day/night camera looks little more complicated for me right now. (camera, housing, and does it need more wires?)

[cctv_down_under 0]

No more wires, but yes generaly a full body camera, there are some that arent but I wouldn't touch them, its not hard to set up, its pretty much out of the box.

 

1/2" Black and white would be good but more expensive than 1/3" black and white and need to buy 1/2" lens which is more expensive.

 

All I am saying is that if you want good performance then a true day night is the answer with IR lighting provided, without IR lighting you can geta fake day/night where the filter isnt removed but it changes to black and white...it wont pick up the IR well though.

 

If you spend the money....Ganz, Bosch or Panasonic make excelllent true day night cameras.

 

You could go for a no name brand but if you were doing that I would stick to only banck and white as less moving parts.....less hassles

[latenightrob 0]

CCTV down under - I appreciate your time, you have given me some things to consider and taught me something. I don't think for my application a true day/night camera is for me although I would like it, just not prepared to spend $400 to $500+, So, I will be looking at the cheaper B/W bullet and I can provide the LEDs.

 

I knew this was going to be a bit of trial and error since this is my 1st taste of cctv, but I am having fun.

[metafizx 0]

you might try IR Iluminators that operate in the 850nm region, which is the type that you can see a glow from.

 

Most of the "IR" cams that you get have this LED, not 940nm. In the visible spectrum, and most cams can see this, unless they have a block filter in the lens.

[dnieweg 0]

Keep in mind that not all black and white cameras have the same IR response either. As you get up into the higher frequencies of IR (more invisible) you'll find that there are even some b&w that have minimal response.

 

That's why most simple IR applications use IR in the 800nm range instead of 900nm range because it is closer to the visible light range and therefore most all cameras will see it.

[latenightrob 0]

Keep in mind that not all black and white cameras have the same IR response either. As you get up into the higher frequencies of IR (more invisible) you'll find that there are even some b&w that have minimal response.

 

That's why most simple IR applications use IR in the 800nm range instead of 900nm range because it is closer to the visible light range and therefore most all cameras will see it.

 

Yeah I am afraid of this, as that adds to my confusion. I would like to just add a simple B/W bullet and use it with my existing 940nm IR, but I may have to as you are saying get the IR @ 850nm for the cheaper camera I will probably get. I was thinking of getting this camera, what do you all think?

~Edit: CR Removed Wen vendor link~

 

KT&C KPCEXH190SWX

 

Again thanks for everyone's time!

rob

[dnieweg 0]

IR response really has nothing to do with price. Sometimes it's the cheapo black & whites that have the best IT response. It's mostly dependant on the chip/

 

Mfg's used to share the spectral response of their chips. I don't know it they do this anymore.

 

But here's the deal .. the higher in frequency (more towards infrared), the less the camera will see it. But if it's a black & white it will probably still see it, it's just a matter of how lit up the area would be.

 

So here's a few simple rules:

 

1) The more covert you want the IR lighting to be (meaning people think they are in the dark and can't see light coming from the IR illuminator) , the higher the frequency (i.e. in the 800-900nm range).

 

2) The higher the IR frequency, the less responsive the camera will be to it.

 

3) The only way to overcome high-freq/low-response is to flood the area with more IR light meaning more power.

 

It's like looking at your room with sunglasses on. If you use high frequency IR you have very very dark sunglasses on so you need very strong light to see. If you use lower frequency IR you still have sunglasses on but you don't need as much light to see.

[roygbiv 0]

IR response really has nothing to do with price. Sometimes it's the cheapo black & whites that have the best IT response. It's mostly dependant on the chip/

 

Mfg's used to share the spectral response of their chips. I don't know it they do this anymore.

 

But here's the deal .. the higher in frequency (more towards infrared), the less the camera will see it. But if it's a black & white it will probably still see it, it's just a matter of how lit up the area would be.

 

So here's a few simple rules:

 

1) The more covert you want the IR lighting to be (meaning people think they are in the dark and can't see light coming from the IR illuminator) , the higher the frequency (i.e. in the 800-900nm range).

 

2) The higher the IR frequency, the less responsive the camera will be to it.

 

3) The only way to overcome high-freq/low-response is to flood the area with more IR light meaning more power.

 

It's like looking at your room with sunglasses on. If you use high frequency IR you have very very dark sunglasses on so you need very strong light to see. If you use lower frequency IR you still have sunglasses on but you don't need as much light to see.

 

Valid comments, unfortunately you appear to have confused frequency with wavelength.

IR is longer wavelength (higher nm) therefore lower frequency than visible light.

[dnieweg 0]

 

1) The more covert you want the IR lighting to be (meaning people think they are in the dark and can't see light coming from the IR illuminator) , the higher the frequency (i.e. in the 800-900nm range).

 

2) The higher the IR frequency, the less responsive the camera will be to it.

 

3) The only way to overcome high-freq/low-response is to flood the area with more IR light meaning more power.

 

It's like looking at your room with sunglasses on. If you use high frequency IR you have very very dark sunglasses on so you need very strong light to see. If you use lower frequency IR you still have sunglasses on but you don't need as much light to see.

 

Valid comments, unfortunately you appear to have confused frequency with wavelength.

IR is longer wavelength (higher nm) therefore lower frequency than visible light.

 

Yep, you are right. I did. Please replace "higher" with "lower" and reread.