How To Clean A Camera Sensor In CCTV Applications.
How To Clean A Camera Sensor – What’s the best way to clean a CCTV camera sensor? The camera in question is a high-end fixed camera in an external housing in which the seals have failed. Will a lens cloth do the trick?
A: Typically, there’s a glass filter in front of the CMOS sensor with the sensor underneath this, covered by a very thin Bayer filter applied directly to the sensor itself. Exactly what the task of the glass filter is varies by design, but typically it improves sensitivity lost by the attenuation of the Bayer filter, as well as filtering UV and IR.
The point here is that you won’t be cleaning the sensor itself, but the glass filter on top of it. Nevertheless, you don’t want to play silly buggers with a sensor filter. The issue if you start rubbing the sensor filter with a lens cloth or lens brush is that you might not so much scratch the filter as smear it with oil or dirt, or add another layer of fibre and dust to the surface.
We’d consider buying an LED loupe, which will allow you to look at the sensor under magnification and light. You’ll clearly be able to see any dust or fibres using a loupe. You can then use a blower and/or a lenspen to clear away any debris.
Experience suggests the blower will get the fibres to move but you’ll need a lenspen to get rid of electrostatically charged dust particles. Any grease or oil residue, as well as thicker layers of industrial dust, will demand a wet clean, which is another thing entirely. A wet clean is a last resort play – you need to be prepared to lose the camera.
All this said, unless there’s something very large on the sensor lens, it’s not going to have an impact on the viewed scene thanks to the inherent speed of CCTV lenses. You might see a constellation of dust specs at f32 when pointing your lens at blue sky, but it won’t be an issue at f1.4 viewing a crowded streetscape.
You can learn more about wet cleaning camera sensors from folks arguing on DPR here or read more SEN news here.
“How To Clean A Camera Sensor In CCTV Applications.”
