vmgtlexi 0 Posted September 26, 2011 Does anyone have footage of a TDN camera (without IR) at night in very very low light? I am trying to get an idea of exactly how “true” this type of camera can see at night in ultra low light and without IR. For example, I am looking at a Pelco camera (link below). Are these mainly for night-time situations where there is some ambient light (street light, etc.), or are they truly able to operate in "darkness"? [edit by mod-store link removed] Any and all video footage, images, and links are appreciated. Share this post Link to post Share on other sites
Birdman Adam 0 Posted September 26, 2011 Any camera will need some sort of light to see, be it visible or IR light. (Heat cameras excluded...) That camera should operate good at low-light levels. The WDR better be pretty darn good for that price though! Here is a video I made of a VCM-24VF from CNB: http://www.youtube.com/watch?v=Gi4zLasNu-w Share this post Link to post Share on other sites
Soundy 1 Posted September 26, 2011 What you mean by "true"? If you're talking about "true" color, you won't get it from a TDN camera, because *by definition* these switch to B&W mode in low light. Here are a couple shots from one of my jobs. Lights visible on the patio are 60W bulbs in hurricane shells: In this one, the patio lights are off - there's a little filtered light coming through the dining room blinds to the right, and from a street light a couple hundred feet away to the left: Share this post Link to post Share on other sites
mike_va 0 Posted September 26, 2011 What you mean by "true"? If you're talking about "true" color, you won't get it from a TDN camera, because *by definition* these switch to B&W mode in low light. My understanding of the term is that true has a switchable IR filter. I have some cameras that are non true "day-night" and all they do is go to b&w at night. And some non true have IR filters some don't. Share this post Link to post Share on other sites
Soundy 1 Posted September 26, 2011 What you mean by "true"? If you're talking about "true" color, you won't get it from a TDN camera, because *by definition* these switch to B&W mode in low light. My understanding of the term is that true has a switchable IR filter. I have some cameras that are non true "day-night" and all they do is go to b&w at night. And some non true have IR filters some don't. Your understanding is correct. Typically, digital sensors are all sensitive to IR wavelengths, particularly as you just get out of the visible light range. IR wavelengths have two detrimental effects on your image: they throw off the color balance and exposure (a scene with really strong IR might end up under-exposed because the camera is compensating for that extra "brightness" that won't be visible to you, for example), and they tend to focus differently than visible light, meaning you can end up with a soft image. But the color caste is usually the main problem you'll see on a color camera with no filter (Rory's posted several pictures elsewhere of how this looks - everything is really green-ish). To avoid these issues (especially the color balance problem), color cameras typically have an IR cut filter over the sensor, to block the IR. B&W cameras don't need the filter because the color balance isn't an issue, which is part of the reason they tend to have better low-light response to begin with. A simple day/night camera will often leave the IR cut filter out and switch between color and B&W, but without the cut filter, it merely attempts to compensate for color balance issues electronically. "TDN" cameras have the filter on a mechanism of some sort that will physically move the filter out of the way when the camera switches modes, thus giving the best of both worlds: better low-light response when they go to B&W, and proper color reproduction in day mode. They also typically require special "IR-corrected" lenses, which have optics and coatings to compensate for how the different wavelengths focus. Share this post Link to post Share on other sites
rory 0 Posted September 26, 2011 Top right is TDN no IR - CNB Monalisa Some other relevant samples: Infrared Comparisons: Dual CCD IR Camera - Color > BW > IR on This has 2 internal cameras, a color and a BW, always better than a single camera trying to perform dual applications - but hard to find these days or more expensive. Somewhat relevant videos: http://www.youtube.com/watch?v=oOQSO8N3YLc http://www.youtube.com/watch?v=YmhQjXMgchI http://www.youtube.com/watch?v=Z9w_KYky3BI http://www.youtube.com/watch?v=J0hv1T_RIo4 http://www.youtube.com/watch?v=INoH7_a_FT0 Share this post Link to post Share on other sites
