View Full Version : High Resolution Cameras
09-02-2009, 12:10 PM
Okay, I am very unexperienced when it comes to cameras and what the different terms, techspeak mean. As I posted in another post, where I am at my exterior cameras are starting to go for some yet to be determined reason. Part of my job requires that I make recommendations for what to replace the broken cameras with, and thus I am looking into different camera models by Pelco (the client prefers Pelco so this is pretty much what I am stuck with recommending). I have noticed that a lot of Pelco cameras say they are WDR or Wide Dynamic Range (or something like that). What exactly is WDR? What does it do? Does it improve focus ranges or resolution? The reason I ask is that one fixed camera (this may be changing to a few more in the near future) cover an outbuilding that is at least 50' away from my main building (this distance varies). Therefore I am looking for a fixed camera that has good resolution so when I do playback and zoom in on a spot, I can at least see what I am zooming on and not just seeing a bunch of digitalized fuzz.
09-02-2009, 12:52 PM
Most cameras are very good at capturing brightly lit images, such as the interior of a supermarket with all the lights on.
Capturing very dark images is tricker, but using a combination of good lenses, special filters, and some pretty sophisticated electronics, it can be done. This is why a camera designated as DN (for day/night) can usually capture an image taken in the dark- for example, the interior of a supermarket with most but not all of the lights off. This is not to be confused with cameras that can capture images in zero light, using an artificial (but invisible) light source in the infrared spectrum.
Capturing images that are partially well lit and partially dark, such as a person being framed in a doorway or standing near a window, is difficult. The camera will underexpose the dark part of the image because it is trying to adjust to the brightly lit portion of the image, which is why you cannot see the interior of the truck in this image:
If you cannot see image, click here (http://www.pixim.com/assets/images/image_resources/ccd_forklift_large.jpg).
High or Wide Dynamic Range cameras adjust the exposure level of every pixel, so every portion of the image gets exactly the amount of light it needs, no more or less, as seen in this photo:
If you cannot see the image, click here (http://www.pixim.com/assets/images/image_resources/pixim_forklift_large.jpg).
You need High Dynamic Range (as Ikegami calls it) or Wide Dynamic Range (as the entire rest of the industry calls it; technically Ikegami is correct but try telling everyone that) if you have a high contrast area to protect. Basically anywhere a subject can use shadows for concealment early in the morning or late in the afternoon, when shadows get long. Examples include parking garages, lobbies of buildings with glass fronts or glass doors, areas where walls offer long shadows, and gates or other traffic bottlenecks where you get a lot of cars shining headlights at the camera.
A good wdr camera should be able to read a license plate number, at night, with headlights on (assuming the camera is placed low and the lens is focused so that you get a tight shot of the front of the vehicle).
Hope this answers your question.
09-02-2009, 01:05 PM
It actually helps alot assuming that I understand this correctly,
The WDR function of a camera works independantly of the resolution part of the camera. A camera with WDR capability will allow me to better see day or night (assuming it gets enough light to see) and in changing light conditions such as outside as the sun moves and creates shadows on or around the targeted area. IT will also help in exterior cameras to see who and what is in a doorway of a building (i.e. a exterior fixed camera watching a storage building's loading dock door).
This also helps in my trying to research different cameras.
09-02-2009, 01:10 PM
Correct! One thing I left out: WDR cameras are typaclly speaking hella expensive, as the kids say nowadays. Specify mostly DN cameras, and only use WDR cameras when you think you'll need them.
09-09-2009, 03:37 PM
Hey FireRanger, the company I work for, 3x Logic, actually designs and sells digital cctv gear. We aren't that far from you either. We're down in Westminster off of hwy 36. If you wanted to come down I can actually show you some of the latest generation goodies that are on the market. We don't sell direct to end users but I have someone we can steer you through that I'll put in a headlock for good pricing. :D
If I can help in any way just let me know.
09-30-2009, 02:14 AM
Therefore I am looking for a fixed camera that has good resolution so when I do playback and zoom in on a spot, I can at least see what I am zooming on and not just seeing a bunch of digitalized fuzz.
For zoom fuction, A PTZ camera with EX-View HAD CCD and better optical zoom will be a good choice.
07-21-2010, 06:00 PM
That was a fantastic explanation! :)
07-31-2010, 03:02 AM
check this high resolution camera
it is from this website: http://www.chinawholesale365.com/high-definition-car-camera-road-camera-car-dvr-china-online-wholesale.html
07-31-2010, 08:15 AM
That was a fantastic explanation! :)
I secomd that!!
I work for a company (as a contract Security Officer) that has as many as 100 interior/exterior cameras (covert and PTZ) in a warehouse enviroment.
We never had any training other than how to move (PTZ) the cameras around.
I have reported on a number of occasions that I was not able to read a license plate (I work 3rd shift) They don't seem to care.
We are luckY to have the CAMERAMAN here
08-02-2010, 11:52 AM
Okay, now I'm blushing.
03-18-2011, 04:04 AM
Nice explanation by CameraMan, It actually helped a lot to understand that fully. with the help of images its again nicely described.
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