Okay this question may do it as least I cannot find the answer in the help or the books.

Lets say you have an animation in Carrara and you want the lights to dim..would you just key frame them like say its 100 at one second and then go to 2 seconds in and set the light to 80 etc...I tried this and they dont do it gradually like an animation they do it abruptly....like a light switch being turned off.........

Please advise and than you.

 Hi Jack,

There is no need to key frame every second unless you want to. For example, if you want the lights to dim over 5 seconds, simply place a key frame at the point in time you want the fade to start and then set the next key frame 5 seconds later with the light as dim as you want it to go. 

As for the light switch problem, it sounds like you have the Tweener set to Discrete. Try Bezier or Linear instead.

Mark

Coirses foiled again!  Seriously thank you very much Mark.