The Vault was made for the Shot on Red film festival. It was a good oportunity to try out some visual effects and try some other techniques in the process. I really wanted to try some extreme lens flares.
So I did the edit and picked out the take I wanted to use.
I did the lightning gun effect. Still pretty normal.
To get the right look in the lens I projected the lightning effect into the Red using the same lens I had used during the shoot. This way the lens flares would be similar to what might happen if any of this was actually real. I then got the same flashes and pops, optically captured, just like the on set lighting.
Combined the layers and did the color grade. Since the flares and effects were already synced it was just a matter of compositing them all together and adjusting the intensity of each layer.
Here is a great description of how they used the same technique of optical capture of lens VFX lens flare for Gravity.
And if you are curious why my lens would flare so much it is becasue it is "the worst lens Nikon has ever made" which made it so awesome.