OK. Let's get technical! IR basically involves it self as the absorbance and therefore re-emittance of IR energy. So YES you will see an effect of water since it sbsorbs IR! Haze is probably NOT IR active in the wavelength range of what your filter is operating at. Gases such at turpentine should be, grass powder ( since grass is IR active ) will be, ect. Which is why I suggested the different material experiment. At least you will get a feel for how different substances interact witht he IR. Don't forget then that, even if there is a dusty haze before a subject you can still photograph it pretty clearly. Because the haze WON"T absorb IR. Does this make sense? Bsteph