Set the fines to any level, it doesn't matter.

I only mean that all revenues collected from the fines must be distributed to the public at large. They must never be treated as a revenue source for the government.

Sin taxes are meant to reduce bad behavior - or incentivize good behavior. Ideally you'd collect $0 in red-light fines because everyone's following the law. If some politician's budget or private company's revenue stream depends on traffic fines they have adverse incentives. I don't want my city council member voting against traffic safety initiatives because it makes people better drivers and that means less money for some other city program.

Back to taxpayers. Subtract only the cost of installing and maintaining the cameras and aggressively audit that annually. Cut everyone a check at the end of the year. Buy each household a pony. Have a really good 4th of July fireworks display. It doesn't matter, as long as the government can't spend it for any government program. (And actually the pony and fireworks programs might be susceptible to corruption - just send a check)

Or in the case of a private company contracted to run the cameras, don't give a private company a contract to run the cameras. At least not a contract where they get paid in proportion to the fines collected.

No one should profit off bad behavior. No government program's funding should have to depend on people driving badly.