This is definitely a ticket worth fighting. You have a strong argument, and with photo tickets there are no witnesses at the trial so you can tell the judge your side of the story without having to worry about a police officer there to contradict you. Good luck!
If you plan to do this on your own I suggest you do some research about red light tickets. There are evidentiary objections that an attorney will make on your behalf. Additionally, there are documents that may be discoverable and obtainable from the company which processes the citations and the company which put the machines in place. I would suggest hiring an attorney to represent you. If you were to do this yourself you are looking at spending the better part of two days in court fighting this, whereas an attorney can represent you without your appearance thus saving you time. Also, the likelihood of success is increased when utilizing an attorney who understands the process. If you do fight it on your own and lose be sure to request traffic school. Some courts try to scare people into not fighting a citation by holding traffic school hostage but this is not permitted. Best of luck!
The above answer is for general information only and is based on the information you posted. Every case is fact dependent, so to get a thorough analysis of your situation, you will need to consult face to face with an attorney licensed to practice in the jurisdiction where the incident took place. Do not conclusively rely on any information posted online when deciding what to do about your case.