Asked to spec a security camera which is a whole new world to me. Some vendors describe their outdoor camera model as “color and day/night”, but their wording implies they are two different features - it’s one or the other. Can it be both? Also, if both, does the min lux rating degrade compared to all B&W?
Looking for factual answers. Any links to websites explaining the technology greatly appreciated.
Seems like my suspicions are correct. Better resolution in B&W. This may explain why the human eye is also more sensitive to detail in B&W than color.
Most consumer systems use IR sensitive cameras that are 640 x 480. The sensors can produce full color images but require high ambient light levels. Below a certain threshold, they produce only BW images.
In BW mode, they will turn on the IR emitters that are usually built into the camera. I don’t know this for a fact, but I strongly suspect that in daylight mode, some sort of electronic IR filter is being used and this simply gets turned off at night.
As to resolution, although 640x480 is still by far the most common, you can find some systems that go up to 1024x768 and possibly higher. This is definitely true for IP/network cameras and it’s likely that this will soon carry over to single purpose surveillance cams.
Sorry I didn’t have any citations for you, but this mostly information I’ve gleaned from having an interest in home surveillance equipment.
edit: something about lux ratings. I don’t think these are terribly reliable so you should see if you can find a review where this is measured independently. Then rely on it only if a manufacturer seems honest about it. Also, lux ratings are often given with the IR emitters on and with the emitters effective range. That’s how you get the so-called zero-lux models.
Low light camera ratings have the same reliability as '70s musclecar horsepower ratings. Sometimes I think they just plain make it up. If you want to see the real deal - .02 Lux at 15fps, go to www.scallopimaging.com and look at the M200. No IR. .02 lux at military ratings is “sliver moon, can’t see hands.” That’s low light.