Installation Help and Accessories
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ir lights
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cam2 - 15 Apr 2005, 04:37 am
Hi,
can any camera work by adding ir lights to the setup?
I have a mini board cam internally will adding ir lights enable the camera to see?
VST_Man - 15 Apr 2005, 05:51 am
ir reflects and will improve a video picture at night. but, the quality of that reflection and the ability of the camera to "see" it depends on the type of camera (cmos, ccd, super had, exview, ect.) and lense (focal length). and, you can buy narrow or wide beam ir.
depending on who you talk to and how they install, some say bullets with ir and others preach seperate the ir and the camera. i say that depending on the customers requirements, install location, actual lighting conditions, enviornment, and budget will determine the equipment installed.
and if you aim a 60ft. ir capable out into dark "space" you will get a video picture of that dark space, which will look dark.
rory - 15 Apr 2005, 05:54 am
All CCD's (color and B/W) are IR sensitive.
Such as the washed out color image you generally find on cheap color bullet cameras, as most of those cheaper cameras have no IR cut Filter - they pick up the Infrared generated by the sun, and other sources, resulting in strange colors. An IR cut filter in front of the color CCD's will show better daytime color.
Color camera - If the color camera has a fixed IR Cut Filter it will not pick up Infrared Light as the filter blocks it out. If it has an auto switching IR cut filter, or if it has no IR cut filter, then it will pick up Infrared Light.
All BW cameras will pick up Infrared Light.
The range of Infrared that the camera will support will depend on the Spectral Response of the camera. Generally all can recognise 700 nm range (like the street traffic lighting), and some will see 800 nm range (faint glow), while only certain ones will go higher into the 900-1100 nm range which is invisible lighting. You will have to check with the camera manufacturer to see if it supports the 900-1100 nm range, though generally if it does, the manufacturer will say so in the Data Sheet.
Certain Chips will support Infrared Lighting better than others, longer distances - Eg. Some Exview Chips giving you an extended IR range for example, or ExtremeCCTV's LRX Chips are designed specifically for long range Infrared.
Once you have soughted out the camera IR support, then you will need to look at what IR Lighting you have, what you want to see and how far, and where it is going (location, surroundings, eg, Bush, walls, etc).
Rory
cam2 - 15 Apr 2005, 08:03 am
This is the caera spec.
Remarkable colour reproduction
Super mini CCD camera, smallest in the world
High-performance CCD color camera over 380 TVL resolution
Excellent auto-white balance realizing true color reproduction against various light sources
Wide range of applications: shops, baby care, private residences, chain stores, garages, banks, hospitals, etc.
Outstanding video s/n ratio of 48dB, noise-free picture
Low power requirement, wide tolerance 8.5V to 15V
Specifications: Application: exchangeable lens, board type
Image: 1/4" DSP color CCD
Horizontal resolution: 380TV lines
Picture element (pixels):
If i fit an ir light in the same room where would be the best place to position it?
rory - 15 Apr 2005, 08:20 am
Thats not the specs we need to go by, thats a description by the storeowner.
need some actual specs, lux , ir cut filter, spectral/ir range, etc.
rory
cam2 - 15 Apr 2005, 08:26 am
Is this it?
Min illumination: 0.2 lux at F 1.4
Synchronization: internal
Scanning system: 2:1 interlaced
Video output:1Vp-p, 75ohm composite
S/N ratio: more than 48dB
Electronic iris: 1/50, 1/60 to 1/100,000 sec
Smear effect: 0.005%
Gamma correction: r=0.45 to 1.0
White balance: auto, 2800deg K to 8200deg K
Gain control: auto, 4dB to 30dB
Lens mount: standard f=3.7 (78')
Audio: available
MTBF: 80,000 hours
Power source: DC12V (tolerance: 8.5V to 15V)
Operating current: 90mA with regulated power
Measurement: 29 x 29 mm (WxV)
Weight (approx): 60g
Cooperman - 15 Apr 2005, 05:09 pm
cam2,
Are you intending to use the camera covertly? Just out of interest, do you have a link to the camera you have in mind?
If you want to use a camera internally with Infra Red, the quantity of light will depend on the size of the room, and the sensitivity of the camera. If it's a 1/4" colour camera, it's probably not the right one for you.
As regards the location for an I/R lamp, for most internal applications it's best to bounce the light off the ceiling, provided your illuminator has sufficient output :wink:
cam2 - 16 Apr 2005, 05:00 am
Thanks,
no not trying to use it covertly, just with it being in my home the cameras always look better when they are not on full view.
I have it in a garden room which covers the rear exit of the house,
to be honest i probably went for the wrong camera for this application!
Maybe be better if i fit a motion detector to the light in the room when it is dark?
kaysadeya - 16 Apr 2005, 08:36 pm
QUOTE:
All BW cameras will pick up Infrared Light.
Rory, I have a B&W board camera that's completely blind to IR light. It’s a covert outdoor camera mounted behind a sheet of special glass originally designed for photographic use with enlargers. Either the glass itself is filtering the IR light or the camera doesn’t pick it up.
I've had if for about 6 years and have long forgotten the brand and specs.
rory - 16 Apr 2005, 08:43 pm
[quote:23f5f9c5ae="kaysadeya"]
QUOTE:
All BW cameras will pick up Infrared Light.
Rory, I have a B&W board camera that's completely blind to IR light. It’s a covert outdoor camera mounted behind a sheet of special glass originally designed for photographic use with enlargers. Either the glass itself is filtering the IR light or the camera doesn’t pick it up.
I've had if for about 6 years and have long forgotten the brand and specs.
Its got to have a filter or that glass is filtering it out, Take the camera out byitself and it should work.
kaysadeya - 16 Apr 2005, 08:58 pm
Easier said than done. :? It's one of my earlier Mad Scientist projects and the camera is “embedded” in something. Figured I'd just throw everything away when the camera failed.
AVCONSULTING - 18 Apr 2005, 12:05 am
Go with the motion controlled light, cheaper, better lighting, and lights scare people off. IR is good for covert or when lights cannot be used because of neighbors, etc.
Cooperman - 19 Apr 2005, 10:50 am
kaysadeya,
The enlarger glass is almost certainly designed to reduce heat from the lamp, passing through the delicate negative. On larger format film materials, if the 'neg' gets hot it will buckle, and at the very least go out of focus (or fry!).
The way the glass reduces the heat passing through is ...... by filtering out the Infra Red :wink:
The point about B/W imagers is that unfiltered, they will have some sensitivity to IR, although the spectral response will vary from one to another.
Some older model CCD cameras were deliberately fitted with IR block filters, most of which could be removed, if necessary. I've still got one old 1/2" CCD camera which 'filter out' will work up to around 1150nM (albeit with a very low response).
kaysadeya - 19 Apr 2005, 11:46 am
Interesting. This is probably the problem. By the way, where can one get optically correct/clear glass that doesn’t block IR light?
Cooperman - 19 Apr 2005, 06:03 pm
Kaysadeya, you shouldn't need to look at optically corrected glass. Most housing windows are either, standard 'float' glass (4 - 6mm thick) available from glass merchants / dealers, or 'lexan' / polycarbonate plastic, which has good impact resistance, but does scratch and weather with age. Both allow clear viewing under IR conditions.
There seems to be some general view that using Infra Red is something of a 'black' art (pun intended). In practice, IR frequencies behave in precisely the same way as visible frequencies, it's just that there generally isn't the quantity / quality of lighting that would normally be experienced with 'white' lighting. Also, with most optics, there is a focus shift which is down to the lens glass bending the invisible frequencies at an ever so slight difference to visible frequencies.
In most situations, if a compromise focus is set for both lighting conditions (at maximum aperture), then the correct focus can be achieved for both by increasing the depth of field (i.e. closing the lens aperture one or two stops).
It's worth considering that affordable IR corrected lenses are a relatively new product, and for forty years or so, engineers / installers had to know how to get the best out of what was available then.
Just realised, this is a bit more info then you were looking for, but hey, it's late, I'm tired, you never know it might be of interest :roll:
kaysadeya - 19 Apr 2005, 06:56 pm
No such thing as "too much infomation" in this forum. Thanks.
Yes, I’ve seen some mentions of “IR corrected” lenses here. Some of my older B&W cameras and lenses do appear a little fuzzy under the Vitek illuminators in the back yard. I’m also using older lenses on my Samsung 721s in the front and the night images appear very crisp under IR from an Extreme UF100 and UF500. Under low light these cameras automatically increase the gain, so maybe this compensates for the focus shift. The high output from the Extreme illuminators might also be a factor. (But even they’re not enough to cut through the IR-blocking glass covering my pinhole board camera.)
rory - 19 Apr 2005, 07:11 pm
I didnt use an IR Lens for any of my IR, yet, wasnt available at the time ..
Cooperman - 21 Apr 2005, 05:17 pm
It kinda proves the point rory; you can get the best out of everyday gear just based on your experience. 8)
Give all the new toys to someone with little experience, and the results will undoubtedly be inferior.
Thomas - 21 Apr 2005, 05:47 pm
Hah! Breaking new toys is exactly how you learn how to get the best out of something.