William Castle was a real PT Barnum, if you pardon the expression. A film director and producer, but also a master showman, Castle dreamt up countless gimmicks for the release of his movies throughout the 50s and 60s.
For 13 Ghosts, which is immeasurably more fun than its remake, Castle had the film released in a process he called Illusion-O. In a nutshell, it went like this: the audience were given glasses much like the red-blue 3D specs of old. If they looked through one eye, they could see the ghosts, if they looked through the other, they couldn't.
Not wearing the glasses meant the ghosts appeared in pale blue. The only way to not see them was with the specs on, one eye closed.
Now, we're hearing that Paranormal Activity 5 might be using a high tech version of this same idea. The details aren't clear, but the basics promise ghosts that can only be seen through a pair of 3D specs.
With normal modern 3D specs this would mean that the ghost would have to be manifest only as volume, not surface detail. I don't know if you can imagine such a thing, but think of a normal flat 2D image, then some of it would be "wrapped" around a 3D space to create the ghost. You could do this with a film meant to be seen in either 2D or 3D.
But I expect it's not that. I expect they'll make a variant on Real D glasses that have both lenses be the same. Then if the viewer watches through the specs they get one set of info, if they take them off, they get both sets of info.
This means that the "left eye frames," say, could contain the ghost image. Watching without specs, you'd see left and right eye frames, and be able to catch the flickery ghost in the image.
Can't you imagine the marketing? About hiding behind your glasses from the ghosts?
Of course, most people wouldn't. Most people would go into it with the specs off. Who wants to see a horror film without the horror? Okay, except for my wife?
There may yet be another way they're planning to do this. Either way, it's an interesting little call-back to the William Castle era and a nice way to inject some interest into the Paranormal Activity series.
Now, while we wait for October and Paranormal 5 to roll around, let's rehearse with some old Castle movies, or Joe Dante's wonderful tribute Matinee, a fictional tribute to the man – ten times better than any of Castle's films but no less enjoyable.