Clever use of the spotlight 
Thank you! I did it in compositing, but the effect is similar. I will share a screenshot of it tomorrow.
Hey, as promised 
The important bit is to set the transparency of the background for it to have effect (I learnt it the hard way ahahah)
Let me know if you have any questions. Have fun!
Thanks for introducing me to the world of compositing, this is really helpful and im getting some trippy results, ill post some when ive had a good play around
Lovely! Compositing definitely is a world on its own within Blender. Those in the image are just a couple of nodes I learnt about here and there, and some of them are not even related to that background you were interested about, but to lens distortion and all. I am so glad I could help on this, and I am sure you will discover more the more you play with it. Looking forward to seeing those results 
Having a lot of fun learning how comping works, some results im happy with and some not so much lol, check out my terminator ten cuber, one again thanks Lucio!
Awesome!!! Jumping straight in to take a look. Hasta la vista for now 