You kids today with your fancy computer graphics. Back in the old days, folks had to do everything with mirrors and trickery. That's what Shanks VX did!
In the video above, Shanks FX uses complicated light painting (long exposure photography) to recreate the iconic proton stream from Ghostbusters without CGI. Granted, it's not exactly how they did it - the original Ghostbusters used traditional compositing over film to create that sweet beam look we all love, but it's still a fun project to do at home. It is also great as a thought experiment to understand exactly what went into those old flicks.
Plus, he's quick to point out that you can definitely make it more convincing with a lot of time, an ND filter and a boatload effort in After Effects.