as far as i can tell, the only filter that makes sense is a gradual polarizer. UV filters do nothing optically. everyone puts them on their lenses, because the effectively protect the front element. thats all. ND filters simply block out light. this makes sense if you want to use a very large aperture in very light conditions, e.g. f1.8 in bright sunlight. for Vision camera it doesnt make sense - it only has f2.8 and closing aperture usually increases lens performance (sharpness, vignetting, etc). A polarizer filters out light that comes in at an angle other than straight onto the lens. on a sunny day the sun will reflect off of many surfaces and bounce around. lenses cannot handle this very well (neither can the eye, hence polarized sun glasses). a polarizer filter will block most of such reflected light. the effect is richer colors and better contrast. I would expect it could very well make quite a difference, judging by what i ve seen from my cameras. Havent tried it though. anyone tried a polarizer?