I4S reader Dale Edginton has this problem with his CCTV system. He writes:
“My CCTV system works fine during daylight hours, but during the night they seem to fog. They do not have water ingress or seal problems. It looks like an over exposed photograph.”
We asked Security Installer‘s CCTV Doctor, Jon Hill, of Siemens Building Technologies Security Products, for his opinion
Says Jon: “There are a number of reasons why the symptoms reported could be occurring.
“Dale mentions that the picture looks foggy and also over exposed. It sounds like the lens view is being obscured by something and when the light level falls, this has a more obvious effect on the picture processing.
“We have no idea what type of camera is being used, or what level of light (IR or white) is available during the hours of darkness.
“I would suggest that Dale takes a closer look at one of the affected cameras to ensure that there is nothing obscuring the lens (no grease smears or fingerprints) and that the general assembly is properly set up – including back focus settings.
“He should test the assembly internally (in the dry) to see if the symptoms persist and thus eliminate moisture ingress.
“One thing to consider…If the cameras contain integral heaters, ensure that any silica gel packs within the camera housings are not charged with moisture. Generally they turn green if this is the case.
“What might be happening is that during the night, as the temperature falls, the heater is switched on which in turn could draw moisture out of the silica gel pack? It’s a long shot, but I need a little more feed back from Dale to understand what could be happening.”
So Dale, if you want to give our Doc a little more detail, click the comment box at the bottom.
And if any other readers have suggestion that might help Dale solve his problem, click on the comment box in the same way.
