I’ve made a lightsaber effect by tracking two dots on a cardboard tube and recorded it. For the effect just used an emission shader and some bloom. Really like how it looks but how can i make light shine on the face of the person holding the lightsaber? somewhat like this:
Even though the footage was recorded in day light I would still like a bit of light on the face.
So, if you want light shining on your talent like in the movie, you most likely will use practical lighting. I shot a Star Wars/Christmas-themed short with my niece, and when that saber was supposed to ignite, I shined a red light on her.
I also tracked my camera, and recreated my scene to do just what you are asking - using “invisible” CG doubles to catch cast off light/reflections/shadows to better integrate the CG elements into the plate.
As you said that you’d already shot your footage, the scene recreation approach will likely be your best bet for any environments, but you may be stuck with manually adding in the glow to your talent’s face, hands and torso.
Here’s my short, and hopefully you can get some ideas from it: https://youtu.be/Nb4tWROZ87A
Well in my case i did not track my camera i tracked the cardboard tube with some dots made with a permanent marker, then in the solve panel i made two empties with the track data then made a cube with the right proportions add an emission shader. To copy the movement i used some constraints and it works very well, Did this following this video on youtube: www.youtube.com/watch?v=bVUeRIY1E-M=) It’s a very helpful. Then looks that i manually add the light i’m thinking that i could use some LED and put on light saber pointing the face or use a LED strip.