NetMedia VIDJBOX-DB - Manual (Page 4)

NM-VIDJBO
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MAN-VIDJBOX REV1002A
NetMedia, Inc., 10940 N. Stallard Place, Tucson, Arizona 85737 (520) 544-4567 Fax: (520) 544-0800 Email: [email protected] www.netmedia.com
Frequently Asked Questions
Q- When using the Dark Lens Cover, why does the picture look too bright, dark, or strange?
A- The dark lens covers make the camera less obtrusive but they may not work well under some conditions. The cover that ships
with the color camera is similar to tinted sunglasses; it needs bright light in order to provide a good picture. The cover that
ships with the B&W camera only passes infrared (IR) wavelengths; it needs incandescent, IR, or sun light in order to show
anything. This can lead to unexpected results. The image will be dark under bright flourescent lights but bright when
viewing dark grass or trees. Vegetation and other items can appear quite strange when seen through the IR spectrum. Use
the clear lens cover when the dark one is not suitable.
Q- When using the Clear Lens Cover, how can I make the camera less visible?
A- Try painting the inside of the lens cover black while leaving a small clear area for the camera to see through.
Q- Why do the light areas of the picture look washed out?
A- The camera’s automatic iris must decide how much to open for shadow areas or close for light areas. When a picture has
both light and shadow, the camera adjusts the iris based on the percentage of each area in the image. If it decides to open
more for the shadow portions then the light areas will be overexposed. In addition, cameras that are designed for low light
or infrared sensitivity typically favor the shadow areas and look more washed out under bright conditions. Try adjusting the
image field so that more light areas are visible and see if the iris closes to improve the picture. It is normal though, that as
the lighting conditions change throughout the day, so will the camera iris and the picture’s dark or light areas.
Q- Why are the shadow areas too dark to see much detail?
A- This is like the washed out question above except opposite. In this case, the camera’s automatic iris is opening more for the
light areas at the expense of the shadow areas. Try adjusting the image field so that more shadow areas are visible and see
if the iris opens to improve the picture. Keep in mind though, that the camera still does need some kind of light in order to
see. If necessary, add some lighting to the dark area to improve visibility.
Q- How can I see the camera on my TV without using an expensive security monitor?
A- The composite video signal from the camera can be plugged directly into one television’s RCA Video Input jack and viewed
when that TV is switched to the proper input. Another option is to feed the camera signal into a modulator. A modulator,
such as NetMedia’s MM70, changes the video to a UHF or Cable channel and allows the signal to be distributed to all your
TV’s along with the existing antenna/cable/satellite service.
Q- How can I increase the length of the power cord?
A- The camera has a minimum power requirement of 12V DC 150mA (it ships with a 12V DC 300mA transformer). You may use
another power supply and cable but the connector needs to be just like the power jack of the included transformer, 5.5mm
outer dia., 2.1mm inner dia., center positive. Do not cut the cables coming out of the camera or you will void the
warranty. Do not reverse the polarity on the power jack or you will damage the camera and void the warranty. The
power supply, along with the cable type and length, will affect the voltage that is available to the camera. There must be at
least 12V DC under load at the camera in order for it to function properly.
Q- How can I use this camera if there is only one coax running to its location?
A- This camera was designed for use with separate power and video cables. NetMedia does however, offer One Wire Video™
solutions for various installation applications. In this case, you could use the Power Over Coax (NM-POCSET) modules to
supply power through the video coax to this camera. NetMedia’s CAModulator products are cameras with modulators
already built into them. They also require only one coax for both power and video. Modulated video requires a tuner for
viewing so monitors, quad displays, and DVR’s cannot directly accept that type of signal.
Q- What do the switches inside the “D” Day/Night camera adjust?
A- The Day/Night camera comes with a switch connected inside to adjust some of its performance characteristics. The switch
functions are listed below (Figure 5). The default settings (All OFF) are usually best but adjusting these may be helpful under
certain conditions. The AGC switch will force the camera to remain in color mode instead of changing into black and white
mode when the light level drops below its normal crossover threshold.
Switch 1: BLC - Back Light Control
Switch 2: AES - Auto Iris
Switch 3: AGC - Auto Gain Control
Switch 4: Unused
Default: All OFF (Away from numbers)
Figure 5 - Day/Night camera switch functions. AGC ON will prevent the camera from switching into BW mode. Default: All OFF.