i have spent allot of time in the past rotoscoping lightsabers, and it was always time consuming. not any more! there are a couple different techniques here, some actions make one saber, others make two.
this is the original image.
this is using the ilm action.
 
this is using the ilm glow action.
this is using the lightsaber one action.
this is using the darksaber action.
now these are for scenes with two different color sabers. (the actions above will not work with two)
this is using the ilm 2 action.
this is the original image.
this is using the lightsaber two action.
this is using the lightsaber 2.1 action.
star wars