Before long day ago, I saw an amazing activity on lighting photography. It's called "Paranormal activities on Lighting Photography" Could anyone explain something how does he do that?
If it's not Photoshop (it can be) you will need:
* a long exposure
* a white laser pointer that will be used to "paint" during the exposure
* and a lot of patience
edit // I think this may be mostly Photoshoped because of some details:
(1) The light must be "on something". In that top zone, the light is just "in air".
(2) Uncompleted reflections
It may be painted with long exposure but completed with Photoshop.
I would probably suggest its Photoshopped.
As vectotialpx points out, the exposure time would be ridiculously long and the patience required would be huge!
It's also a bit too 'clean'. the lines are all a bit too perfect if you were stood with a laser pointer .
Grab a photo, stylus and drawing tablet and get to work.
Use the brush tool with sensitivity and pressure modes active.