Need help understanding basic IR video surveillance

[toddraleigh 0]

Hi. I would appreciate any help anyone can give me. I'm in a learning mode. I'm trying to piece together a video surveillance system for my home. I know very little about this so I am conducting some research. My comments may be all over the place, but bear with me.

 

I prefer to have day/night cameras with 950nm IR for night time use due to the red light issue. I don't really want anyone to notice the light. If it ends up being too expensive, I'll have to go with 840nm.

 

I have the need for 6 outside cameras:

qty: 1 @ 5 to 10 feet

qty: 2 @ 10 to 20 feet

qty: 3 @ 60-80 feet

 

I also would like 2 inside cameras:

qty: 1 @ 10 to 15 feet

qty: 1 @ 15 to 20 feet

 

It would be nice for the inside cameras to be 950nm and be either fake PIR or be housed behind a wall-plate with a pinhole view, but I don't know if anything like that exists on the market.

 

I bought a Zmodo package on Woot for about $280:

http://www.woot.com/Blog/ViewEntry.aspx?Id=18505

 

Really cheap. I know. But it gave me an understanding of how this stuff works. The package contains 8 cameras (CM-C11313SV) and an 8-channel DVR (DVR-H9108V).

 

The cameras aren't very crisp or clear for night time identification. Rather poor quality. I don't know what specs to look for on a camera to get crisp and clear images in both daytime and nighttime IR modes. I have no idea what technologies exist for the image sensors or the actual number of LEDs that are needed for IR. In fact, could I use 950nm illuminators for any IR camera? I don't know. What's the maximum number of TV lines you can get from a camera? The most I seem to find are around 540-600. How much superior is that to 420 lines? Can someone point me to some comparison photos (night time). Maybe someone can help be out given my distance specs above. The specs on the cameras that came with the package are:

 

Image sensor: 1/4" Color CMOS

TV Lines: 420

IR LED: 12

Lens: 3.6mm

 

The Lens diameter seems to be directly related to the field of view and maybe the ability to see further away?

 

Also, I am finding it very difficult to find video on the web of actual night time IR surveillance replay – especially with faces. Maybe IR technology isn't sophisticated enough to really capture clear crisp images. It would be a great selling tool to show actual video in scenarios like that. After all, if you can't get a crisp image, why bother with the video?

 

So, if you can help me by answering any questions above, providing any practical information and/or lessons learned, I would appreciate it.

[Soundy 1]

Also, I am finding it very difficult to find video on the web of actual night time IR surveillance replay – especially with faces. Maybe IR technology isn't sophisticated enough to really capture clear crisp images.

I think your problem here is that you're approaching the whole thing with a misunderstanding of what "IR" actually does in this context. There's nothing special or magical about it; these aren't thermal-imaging cameras or anything high-tech like that. In your case, you're looking at very cheap, bottom-of-the-barrel cameras that have very poor ability to "see" in low light... and so to compensate, they add a bunch of two-cent LEDs that emit light at the fringe of the visible spectrum. Imagine shining an LED flashlight to illuminate your subject... except it's near-IR instead of white light: invisible to the human eye, but visible to your average camera sensor.

 

Now there's an inherent drawback to this: there's lots of ambient IR and near-IR light in nature, and because the camera sees it while we don't, it can throw off a camera's exposure and color balance. To avoid this, color cameras normally use an IR-cut filter over top of the sensor, to block the IR. Naturally, that would also block the illumination from the LEDs... so cheap cameras simply do away with the filter, and compensate for the exposure and color balance electronically (and usually poorly). Because IR light focuses "shorter" than visible light, that also means they don't always have very sharp focus.

 

"True day/night" cameras use a removable cut filter that the camera flips out of the way when it switches to "night" mode (which also typically includes switching from color to B&W). These tend to cost substantially more than your cheapie cameras, though, and there aren't a lot of models have have the LEDs built-in, relying instead on external illuminators that can be better selected and installed to optimize coverage.

 

As for video showing "IR surveillance" - there's tons of it. The vast majority of "stupid criminal" clips on YouTube come from cheap systems with cheap IR cameras. You can recognize it from the pasty greenish-white skin and glowing eyes of the perps.

 

It's not that IR technology isn't "sophisticated" enough, you see... it's that it's most often used with cameras that simply aren't of high enough quality. A good low-light, true-day/night camera (such as the CNB Mona Lisa models) will often do better with very little ambient light, than a cheap camera with built-in IR.

 

As far as 950nm vs 840nm, keep in mind that you won't see the 840 illuminating anything... all you see is a faint red glow when you look at the LEDs themselves.

[rory 0]

some samples

viewtopic.php?f=5&t=26595

viewtopic.php?f=5&t=26595&start=15

 

http://www.youtube.com/watch?v=J0hv1T_RIo4

http://www.youtube.com/watch?v=Z9w_KYky3BI

 

follow suggestions on right side for more example videos ...

 

And its generally difficult to find 900nm range IR bullets.

[Birdman Adam 0]

I wouldn't worry too much about the faint red glow of cheaper IR (not completely covert). For me, trying completely covert IR has been a hassle and very expensive. Basically, I'd only use it if my house was a military base or something!

 

Rory - in your second video, it looks like the guy has a big knife in his right hand.

[rory 0]

Rory - in your second video, it looks like the guy has a big knife in his right hand.

its a steel stick, cant be too careful!

the machetes are hidden in the bushes for quick access

[Birdman Adam 0]

A steel stick? Ouch! Oh, also I just noticed the magnetic contact on your door.

 

To the OP: Also, I wouldn't recommend cameras with built-in IR. You are just asking to be forced to clean it every couple months to keep the bugs off. Also, some cheaper cameras are not designed well, and the IR distorts the picture (leaks right into the lens, etc).

 

It may look a little uglier, but separate IR illuminators is really the way to go!

[rory 0]

Alot of times, least with the jobs Ive done, have no choice but to use IR, if they are dead set against installing additional visible light and the area is too dark - even with the Monalisa that will see in very low light, as in that screenshot I posted in the link above, its still not good enough to identify them as its just too dark (can barely see to walk). Also same goes for alot of retail, though sometimes you can convince them to leave at least one light on, or use motion lighting.

 

BTW I clean all my outdoor cameras the same time ... water drops matter even without IR. Its the darn spiders that are the problem with some IR cameras, not all locations though, for example at a home here with 15 outdoor IR cameras, only 3 of them seem to be an attraction to spiders, and in that case a little bug spray around it helps (until it rains).

 

Separate IR is always better though, better for adjusting the IR beam as well.

[Soundy 1]

Also, I am finding it very difficult to find video on the web of actual night time IR surveillance replay

Its the darn spiders that are the problem with some IR cameras

 

[Soundy 1]

The Lens diameter seems to be directly related to the field of view and maybe the ability to see further away?

 

The focal length is what relates directly to field of view, and with it the distance you can see. Check out some of the examples here:

viewtopic.php?f=5&t=24549

 

The diameter of the opening is called the aperture, and affects the amount of light it allows and the depth of field.

[shockwave199 0]

Its the darn spiders that are the problem with some IR cameras, not all locations though, for example at a home here with 15 outdoor IR cameras, only 3 of them seem to be an attraction to spiders

Same for me. My two are the ones that have tree limbs up above- pretty far above and to the side too. They shoot webs down, and it's always a single strand- not a whole web. But orb spiders don't get crazy here for another month- then we'll see.

 

Soundy, in one post put together the most easiest to understand wrap up you could ask for. Me being a newbie too, I thank you for that Soundy. That info really clicked in my head that time. It gets tough trying to learn from snipets all over the place. All in one post is a good thing.

 

To the OP- with this stuff it's all about quality components and that equals money. LOTS of money. Ask the pro guys here how much the camera costs if you see a picture you think is really great. It's gonna cost serious bucks to truely superior images. Then multiply that by eight cameras. Factor in the cables and dvr- the cameras are only as good as the gear feeding them. All bucks. That's why you and I, newbies, figure something like this may be enough-

 

Image sensor: 1/4" Color CMOS

TV Lines: 420

IR LED: 12

Lens: 3.6mm

 

I sure did. But after all the hell of install, it's not nearly worthy of that effort. But it's not realistic, at least for me, to have a budget of 2-3 G's for eight very decent cameras. So being stuck in cheap-gear land there are compromises. One of them is superior night image quality. All I can hope for at this level is the least amount of noise. Perfect recognition? I'll make a vid of my new cameras and by Sunday night we'll both see how far I got with that. Mean time, I can offer some comparison pics of what I had, which is LESS than you have at 400tvl, and what I have now- mostly 520 tvl's with better specs. These four pics were screen shots with the channel settings at low bit rates and medium resolution set in the dvr. Hense, they aren't as crisp as they can be.

 

400tvl 1/4" 3.6 cmos-

 

 

520 tvl 1/3" 3.6 CCD w/Sony super HAD-[whatever the hell that is]

 

 

The 400 at night- it has 24 IR's spec'd at 30-40'. I was asking about that in this shot

 

 

The 520 with 36 LEDS- bigger & better looking LEDS, spec'd to throw 32-50'

 

 

This is a night shot of remote view with 520 tvl's and one 560tvl- that one being on the car in the driveway

 

 

Different night views

 

 

 

This weekend I'll make a vid and see how good I look on these cams at night. Am I expecting superior recognition quality? No. Just how good it is, we'll see. Hope some of this helps.

 

Dan- in cheap land just trying to keep an eye on things

[Soundy 1]

To the OP- with this stuff it's all about quality components and that equals money. LOTS of money. Ask the pro guys here how much the camera costs if you see a picture you think is really great. It's gonna cost serious bucks to truely superior images.

 

....

 

But it's not realistic, at least for me, to have a budget of 2-3 G's for eight very decent cameras. So being stuck in cheap-gear land there are compromises.

 

As with so many other industries where you get what you pay for, it's generally a matter of prioritizing. Do you spend the money on a good DVR and cheap cameras first, or start with good cameras and a crappy DVR, then upgrade the DVR later as budget permits? There's no single answer for that - it all depends on the individual needs.

 

In the case of CCTV, a good camera will generally serve you well for many years, and while analog camera technology IS still seeing breakthroughs here and there, for the most part, it's peaked, so if you put some extra bucks into a couple of quality cameras, you'll have something you can build around. DVR technology, on the other hand, is accelerating and getting cheaper quickly, so it might be preferable to start off with a cheaper recorder to go with those cameras, and plan to get something better a little ways down the road.

 

Of course, if you're just a tinkerer, you're probably going to be on a constant upgrade cycle of one thing at a time as you find good deals, used treasures, etc.