Noisy Image; Image Too Dark Or Too Light - FLIR Nexus Configuration Manual

2 Basic Operation and Configuration
2.8.8
With the analog video signal, a noisy image is usually attributed to a cable problem (too long or
inferior quality) or the cable is picking up electromagnetic interference (EMI) from another device.
Although coax cable has built-in losses, the longer the cable is (or the smaller the wire gauge/
thickness), the more severe the losses become; and the higher the signal frequency, the more
pronounced the losses. Unfortunately this is one of the most common and unnecessary problems
that plagues video systems in general.
Cable characteristics are determined by a number of factors (core material, dielectric material and
shield construction, among others) and must be carefully matched to the specific application.
Moreover, the transmission characteristics of the cable will be influenced by the physical environment
through which the cable is run and the method of installation. Use only high quality cable and ensure
the cable is suitable to the marine environment.
Check cable connector terminations. Inferior quality connections may use multiple adapters which
can cause unacceptable noise. Use a high-quality video distribution amplifier when splitting the signal
to multiple monitors.
2.8.9
By default the FC-Series S thermal camera uses an Automatic Gain Control (AGC) setting that has
proven to be superior for most applications, and the camera will respond to varying conditions
automatically. The installer should keep in mind that the sky is quite cold and can strongly affect the
overall image. It may be possible to avoid a problem by slightly moving the camera up or down to
include (or exclude) items with hot or cold temperatures that influence the overall image. For example,
a very cold background (such as the sky) could cause the camera to use a wider temperature range
than appropriate.
There are five Scene Presets that use a combination of settings to produce different configurations
that could improve the video image for a given set of conditions. The presets can be toggled with the
Scene Presets button on the Live Video page.
The presets can also be selected from the Scene Presets in the Setup page. Refer to section 3.1
"Thermal Image Setup" on page 3-1
427-0030-00-28 Version 110

Noisy image

Image too dark or too light

Scene Presets
Scene Presets
Jun 2013 2-21