NetMedia MODEYE-DN - Manual (Page 4)

NM-MODEYE
Frequently Asked Questions
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 do I find out if the camera is working when I can’t see it on any televisions?
A- Start with a basic setup: connect camera to coax, coax to power injector, power injector to TV with no amplifiers, splitters, filters, cable boxes
or other devices involved. Set the camera to a channel that matches the TV mode: 14-69 for Antenna tuning; 70-94 or 100-125 for Cable
tuning. If the TV can tune channel 70 or above, then it is probably in Cable tuning mode. Set a simple channel like 20 or 120 and look for it on
the TV. Check power, power injector direction, connections, cables, TV tuning mode, and camera switches to correct any problems. You must
see the camera picture to confirm that it works in this basic setup before moving on to more complex setups.
Q- Why does the camera or cable service picture go bad when the two are combined together?
A- The signals should be combined at the beginning of the distribution system before the cable service goes through any splitters. Make sure
you are not using any diplexers to split or combine. Once done, there is either interference or the signals are not balanced. Most
interference comes from invisible digital data that is on the line even when not subscribed to it. Set the camera for a clear channel, try 120,
or use a filter to remove the digital/analog interference. When there is no interference you can balance the signals by amplifying the
weaker, snowy one before the two are combined. 10 to 20dBmV is usually enough, too much will degrade the other signal.
Q- Can the camera be combined with digital cable service?
A- Yes. The difficulty is in finding a clear channel for the camera. The digital data usually takes up the analog channel range of 80-117 so
channel 120 is a good place to start. Analog 120 on the TV will not conflict with digital 120 on the cable box. If you cannot find a clear
channel then you will have to use a notch or low pass filter on the cable service before you combine it with the camera. Make sure the filter
does not remove any subscribed digital services including an Internet connection. If only one location is using the digital services and it
does not need to see the camera, you can split its run off before the main line is filtered and combined with the camera. This prevents the
filter from disrupting the digital data while enabling the camera to appear on the rest of the TV’s.
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 in Figure 4. 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.
Q- How can I see the camera when the TV uses a cable box?
A- There are a few ways but they all involve bypassing the cable box and using the TV tuner to see the camera. Combine the camera with the
cable service and check its picture by connecting the coax directly to the TV. Any splitters, filters, or amplifiers you use for combining are
separate from the ones used to bypass the cable box. After verifying the camera picture, split the coax two ways with one side going to
the cable box. If you use the cable box S-Video or composite output then the other side of the splitter goes directly to the TV. If you use
the cable box coax output and there is only one coax input on the TV, then you must use a ch. 3/4 filter (included with NM-ACB3) and
recombine the coaxes as shown in Figure 5. In any case, view the cable box through the appropriate TV connection, Video 1, ANT 2, channel
3/4, then change the TV (not the cable box) to the camera channel.
NetMedia, Inc., 10940 N. Stallard Place, Tucson, Arizona 85737 (520) 544-4567 Fax: (520) 544-0800 Email: [email protected] www.netmedia.com
MAN-MODEYE REV1002A
Figure 5 - Bypassing a digital or analog cable box and recombining to a single coax input on the TV. The kit’s filter removes any conflict on
channel 3 or 4. Switch TV from the cable box to the camera channel.
Power Injector
Camera
Main cable or
Antenna
Splitter/
Combiner
Optional Ch. 70-74 Notch Filter
when there are no clear cable channels.
The notch filter does not bypass the cable box.
Television
Cable Box
NetMedia Cable Box
Bypass/Combiner
Kit NM-ACB3
The kit filter does not
make clear channels
for the camera.
Figure 4 - Day/Night Camera Switches
Switch 1: BLC
Switch 2: AES
Switch 3: AGC
Switch 4: Unused
Default: All OFF