It seems that the red light fines are more or less standard, and everyone knows about them...they are uniformly Sfr 250, and that's that (mine was for 2.5 seconds...who knows, really?).
However, I would advise against contesting fines here in Swissy. A friend was fined via a blitz (camera) for going 3 km over the speed limit in Zürich. She was absolutely sure she was not speeding and wrote a letter claiming that fact. The authorities, always polite, agreed to review the case. They wrote back and said that they would check the equipment. One month later, she received a thank you note from the authorities. In this note, they advised that they had carried out lab tests, recalibrated the equipment, found that the devices were working properly in the first place. The punch line is that she had to pay the original fine and was charged an additional Sfr 500 for the lab work that was used on the test.
So,
Crime, speeding, and passing red lights on amber, or worse, red...only pays for the police.
Good luck.