Right turn at red light -- Ticket in Chicago, IL -- Any way to contest this?

I am originally from Nashville, TN and have been driving in Chicago for less than a year. I received 2 tickets in the past 2 weeks for turning right at a red light. Picture stills and video footage was provided when I looked up my citation in the city's website. My reason for wanting to contest this ticket is, I honestly did not know I could not turn right at a red light (unless there is a sign posted which I always abide by). Since I received the first ticket in the mail, I have not made this violation again. But then I received the 2nd ticket for the same violation, but this occurred before I received the first ticket. Is there any way I can contest these tickets by pleading ignorance? I was not issued an IL license (changed from TN) until last year. I've lived here the past 8 years, but have always used public transportation.