If a speed camera photo is blurry or dark (like in a place with darkness most of the year) the case is as far as I know closed and no inquiry is made.
If I realize too late that I’m going to speed past a traffic cam then I usually just hold my hand up near the wind screen to cover my face and the risk of a ticket would be nearly zero.
There has been talk of making it an administrative fee rather than a crime (like parking tickets) which would make it possible to attribute to cars and not owners.