I just got flashed last week up in PA...I had to make a split second decision as to whether I could stop when it turned yellow without getting hit in the arse and decided to keep going...saw it turn red just as I was passing under it (very short yellow I might add) and then in rear view saw the flash.
Bastards.
There are yellow minimums plus a lawyer might argue some constitutional issues on this.
Fight it and ask the judge to allow you to subpoena all photographic records of your incident. If the car behind was close enough - and shows up in a photo - the judge may see your point and find in your favor. Probably not, but maybe. It never hurts to try.