I am playing with lights to have more reality on scenic, since I can create mood atmospheres. Maybe I am going to wrong way.
My first try was get a ball, make it transparent, applied a material. I was thinking to add a light inside this ball to get mood effects. The first "problem" is I cannot see light to adjust it inside my ball. Also, I have to group both (ball and light) so I can move them where I want. How can I do that?
I just found that I can also apply filters on cameras (another option to get moods or the right way to get mood effects?). Does someone knows where I can find tutorials for that? Or if I am not asking too much, give me a clue? Thank you very much in advance!

You attach an image node to the light to make the filters work (if I understand what you mean). If you change the light to a spotlight you should be able to see it inside the ball, you can change it back to infinite before rendering. If you make the ball parented to the light and then move the light that should work.

Better to change the light to a spotlight, then parent it to the ball, then convert back (if needed) to infinite. You can't parent an infinite light directly. If it is an infinite light, only the rotation settings of the ball will influence the light, translations won't The idea of attaching a node to the light in the material is probably the way to go. As far as I know, it's not possible to put a filter on a camera. You can play with the depth of field settings, depth cueing settings and motion blur though.