Coincidentally NASA's Cassini imaging team lead, Dr. Carolyn Porco was on the BBC's Stargazing Live recently, talking about some of these images among other things. She started out as a member of the Voyager imaging team where the sensors of the day had only 1 Megapixel (and that would have been top of the range, thinking back to my time working on CCD cameras in the late '90s).

It's interesting to reflect that the state of the art instrumentation that's sent up with these long range missions is obsolete by the time it reaches its target.