Yes you have that option..at least we did on Adventure of the Seas.
If the film is 800 the xray can hurt it, anything below that you are fine. The big thing is DO NOT put any film in your checked baggage because the xray is more powerful for checked bags than it is for carry on luggage and can hurt film.
I'm a new federal security screener at the airport and YES you can and should have any film with speed of 800 and higher, hand checked. Do not put it in the checked luggage but instead, carry it with you and ask TSA to hand check it rather than X-ray it.
All TSA employees know that 800 and above s/be hand checked. We do it all the time. I would also ask at the cruise terminal, as all luggage is X-rayed there also.