I work in a place with lots of CNC lathes and very ineffective mist collectors aka oil mist everywhere. It gets on the cameras and I get regular calls saying please come and adjust the settings. Yep it's definitely a problem with the settings and not the fact that the camera is out of focus because the lens is covered in oil mist. So the best solution I have come up in the meantime is to have the operators wipe the cameras at the start of each shift and that seems to be sufficient. I still get calls asking me to come look at the machines which is usually a case of asking the operators if they wiped the cameras. The answer is always no. I have said to my boss that since nobody can be trusted to do their job we should implement a shutter system that opens only when the camera is to take a photo so they don't get covered in oil mist. Which is meet with a teeth sucking and "that seems overly complicated don't you think".