Maintenance =========== .. warning:: Please be extra careful when cleaning the lenses. Follow the instructions below. Otherwise there is a risk of leaving scratches on the lens. Do not try to loosen or unscrew the lens or camera modules. Doing so would damage camera calibration and may void the warranty of your product. .. _lens-cleaning-link: Lens Cleaning ------------- Always start with a **dry cleaning** procedure: Use a blower or a soft brush to remove dust or other loose particles. Avoid using compressed air. To get rid of more persistent dirt you may employ a second **wet cleaning** step, please use a piece of microfiber cloth or a cotton swab soaked with lens cleaning liquid. Appropriate products are commercially available. Alternatively, such solutions can be mixed from diethyl-ether and isopropanol (purity 99% or higher) with ratio 1:1. Camera Calibration ------------------ The cameras are already calibrated when you receive the device. Applying physical force, for example when the sensor is dropped, may have a negative impact on the calibration. If the cameras need to be recalibrated, please ship the device back to us.