IR Backscatter From Scratched Dome Camera Bubbles
Dome camera IR array with bubble removed - astute readers should note such issues are not brand specific.
Has SEN heard of an issue with some dome camera bubbles relating to IR light being reflected back towards the sensor from a scratched bubble after routine cleaning?
A: We have heard of this issue but have not observed it in the field. Apparently using typical cleaning materials – this might include polymer-based cleaning cloths – dome bubble coatings can be scratched, and the accumulation of these tiny scratches may cause IR light to scatter back towards the camera sensor leading to IR blooming. While we have not seen this in practise, the effect can be sufficiently bad that cameras are functionally blinded.
Using cleaning methods like low pressure water nozzles (if IP66 housings) or cloth made of softer materials, including natural fibres, may help, but there’s no guarantee there won’t be some impact over time. Apparently, the damage is a similar to using cotton to clean expensive sunglasses – the coatings will wear away.
Hydrophilic titanium dioxide coatings, which shed water and accumulated dust when sprayed with water are likely to eliminate the issue. Microfibre camera lenses cloths may help but cleaning external poly housings is not their usual forte, so there will need to be some experimentation. Obviously, try to avoid abrasive cleaning products, even when trying to remove difficult to shift accumulations. Always remember plain water is the greatest solvent in the universe.