Once a month on average unless we get a nasty storm with wind that throws a bunch of junk at them. Usually a simply moist paper towel...after first swiping with a clean tissue to make sure no sand granules get scraped across the glass...
Never do really. All cameras are mounted under soffit and I don't have any issues. A few times a year I have to grab the duster on the extension pole to clean up a few spider webs, but that's it.
I got lazy and hadn't done it in five months or so. It's one of the best things to do to regain the great picture a camera gave you initially. No matter how protected you think your camera is, the lens always gets dirty. Well worth cleaning them.
If you mean actually getting a cleaning solutions and cloths to clean off the lenses, never. If you mean sweeping cobwebs, that seems like a twice a day chore lately.
Yea those spiders... Always a web somewhere close to the camera lens that causes erronious triggering. I try to sweep around the front of the cameras every evening. Don't really ever actually clean the lenses though, they seem to stay clean.
Ive got one 5231 Starlight on the side of my barn completely exposed to all the elements, sun 24/7 and rain. I'm amazed at how the picture is always good. Sometimes when it rains i Wil see a few drops on the lens, but that clears up quickly. Maybe it is dirty and i just don't know it... But it seems good. Been up for 3 months now. My old Hosafe bullet that was in that location was always good too.
I didn't clean mine for 6 months as they were not accessible through winter. The constant rain and snow kept them pretty clean. Then I noticed my 30x didnt have fine details when zoomed. I cleaned it and what a difference it really made like @Shockwave199 said. You dont notice the difference until you clean it.
I put a thin layer of vaseline around my camera housing near the front and that had substantially lowered the number of spider and spider webs in my camera view.