Ok, when the Ghostbusters shoot the streams they are squiggly stringlike beams. On GB1 when they shoot Mr. Stay Puft for the first time it shows a far away view. Why are the streams straight in this scene?

maybe. maybe not. its hard to tell. they might be wavy, but since it a distant shot, it may appear that the beams are stright. (either that, or the FX people got lazy)

I vote they got lazy. Maybe they had a long night. That's what I would do!

Probably because unless it's Louis using a proton pack, the beams son't waver that much. And from that distance, you probably wouldn't be able to see it that well.

I Vote lazy FX people

Maybe they put them on highest setting possible. They do wave ever so slightly, like a /\/\/\/\ effect on the edges. But they probably just thought that if the beams went wavy they would hit the building or each other. Not to mention it looks cool like that.

If you want an answer that fits within the realm of GB. let me offer this to you; Picture a hose that has one of the nozzles that you can turn off at the end with the black knob. There is always an amount of pressure trying to force it's way out. If the knob is half-way closed, the water hits it, and 100% of the pressure is trying to come out of only 50% of the opening, and makes the water spray everywhere. However, if you open the nozzle up completely, the water isn't hitting anything and comes out in a nice straight stream. So maybe apply this type of idea to the proton streams in that when they bust something like Onionhead/Slimer, they only need minimal power and therefore only “open up the streams” part way. Gozer/Stay-Puft is huge and needs all the fire power they can get, so they open full stream, and they are shoot in straight lines, for nothing is holding back the streams. I believe at one point they even say “full stream”. Just an idea and an attempted analogy.

It just has to do with what the proton guns were pointing at.. say point A is the gun tip, and B is where the pyro is going off.. it isn't always going to be a straight line.. because the actors don't always know where to point it at.. and such as in the hotel Egon blasting the bar scene.. he had his gun aimed up, but they particles needed to go to where the pyro was going off.. so the FX people drew the line in at an angle..

I don't know about you.. but that really just confused me..

Okay people, I have it figured out. The proton packs are positive energy, the ghosts are negative energy. Opposites attract.

When they shoot at Mr. Staypuft, it would've been very unlikely that they'd accidently point away from him, since he's so large. So the beams would go straight to him.

Now, when Egon shot at Slimer, it woud be very easy to shoot in the wrong direction. Notice that it comes out straight in the begining and then bends to hit slimer, because of the opposite energies.

I hope this helps, and i hope even more that you understood it.