[mikeerdas]

Disney's Haunted Mansion, as most of us know, houses the world's largest known Pepper's Ghost effect in its Ballroom scene. One of my all time favorites. However, something puzzles me. If I remember correctly, most descriptions of Pepper's Ghost effect implementations emphasize a 45 degree tilt to the glass as being essential. However, it seems in Disney's Haunted Mansion's ballroom, the glass is aligned vertically, with no tilt at all as you see if passing by on your Doom Buggy (omnimover) ride vehicle.

I understand that the animatronics that appear in the scene are beneath and above the ride vehicle track. But if the pane of glass is straight and vertical from top to bottom, how is the effect achieved if a 45 degree angle to the glass is required? Is there more than one pane of glass to this effect? Or is the 45 degree angle simply not mandatory to achieve the effect?

I may either be confusing this with other stage magic effects, of the Headless Person variety, where two mirrors need to be at 45 degree angles such that they reflect, say, a table or wallpaper pattern, with the result of the rest of the person seeming to be absent. May also be confusing this with a Blue Room sideshow effect, e.g. girl-to-gorilla or ghoul.

Or is the key to a Pepper's Ghost effect not so much the alignment of the glass / reflecting surface, but rather the viewing angle?

 

[annamarykahn]

although i've never been and seen the effect in person ...

or maybe the projectors are located so that the glass is @ 45degrees to the projector and the doom buggy? set up such that the projection beam is 90degrees to the people in the doom buggy?

maybe a scrim is used? i really have no idea

amk

 

[Evil Elf]

I would think that, yes, it depends on where the viewer will be as well as the source of the "ghost". In the case of the ballroom scene, the "source" does not need to be hidden from the viewer, so the glass is perpendicular to the "source ghost".

Where as most set-ups use one floor, the 45 degree glass is essential, as seen below.
(the red box is the viewing area)

 

[TNBrad]

I think I remember see a video on you-tube about history of the glass. And there maybe two pains of glass, the effect glass in the ball room and a second along the tracks. As years-ago someone's kid took a pelt gun on the ride and shot the effect glass (not disguised as a spider web).

 

[Sinister Sid]

It all depends on your set up. No it does not have to be at a 45 degree angle. It's all about the reflection. If you have something above or below like the haunted mansion it can be a direct reflection. Most peppers ghost illusions are done on the same level which is why the 45 degree angle is necessary. It is just a way to hide your ghost source.

 

[Icepick]

SPOILER ALERT::::::::::


If you go to EPCOT, and ride "The seas, with Nemo and friends", when you get towards the end and the fish are in the "live" tank, lean forward and peek above and behind your clam mobile. This will reveal how they achieve peppers ghost for that particular ride. The HM is basically done the same way, but instead uses animatronics, a black room, and lighting, to get theirs done. Disney has been using more and more projection effects, which I think is great. I just hope that when they convert an old school trick, to new technology, they don't lose the essence of their attractions.

 

[Sinister Sid]

Disney also uses a projection to create the ghost on the Tower of Terror. The ghost appear during the ride on your way up to the drop flloor. It looks like they still used the 45 degree angle to hide the projector. You can see the angle of the glass on the tile floor.

 

[CDW]

It's mainly a question of where you want the image to show up. Most home haunts want a ghost hovering right in front of the audience; in order to achieve this, you need a 45 degree angle with the original object, because that's how the light reflects. The effect works because our brain interprets the reflected image as a real object in a straight line through the glass, because we're better at seeing and understanding real things than reflections. If you'll notice at the Haunted Mansion, there are no ghosts directly in front of the viewer in the ballroom, only above and below. Take a look at these diagrams to see what I mean:

Haunted Mansion:


Home Haunt:

 

[victor-eyd]

Here's a couple of cool youtube videos detailing the pepper's ghost

Victor

 

[mikeerdas]

Thanks to all for the great info and especially the diagrams. Didn't realize a 45 degree glass angle was only required on a same-level line-of-sight implementation. @IcePick, thanks for the tip about Nemo. Will definitely remember to turn around while on that attraction during my next visit to EPCOT. May not be for a while. Next trip to Orlando is dedicated to the Wizarding World of Harry Potter--both the new Diagon Alley and the older Hogsmeade area. Looking for every interesting special effect I can spot.

I'd really like to know which technology is used for gesture recognition; e.g. at certain window displays, you wave a wand in a particular path--and doing it correctly causes a display in the window to activate. Wondering if it's something like the Kinect, where an Infrared "point cloud" / "point web" is spread out in the area where the person with the wand is standing. They tell the little kids to speak the spell; but evidently all that's required to activate any given window display is to move the wand in a particular path.

 

[CDW]

I'd really like to know which technology is used for gesture recognition; e.g. at certain window displays, you wave a wand in a particular path--and doing it correctly causes a display in the window to activate. Wondering if it's something like the Kinect, where an Infrared "point cloud" / "point web" is spread out in the area where the person with the wand is standing. They tell the little kids to speak the spell; but evidently all that's required to activate any given window display is to move the wand in a particular path.

This article and the discussion here indicate that the wands have an infrared reflective tip, and the displays have IR emitters and cameras. Then the camera just has to track the bright infrared spot to detect a gesture. It's a pretty smart way to do it; cheap to implement, and the wands don't have to have batteries. Downside is that the wands don't do anything anywhere other than Diagon Alley (or is that an upside? ).

 

[Sinister Sid]

Yes. The wands are infrared. You can see the difference from the older wands compared to the newer wands. The newer wands have a reflective tip that looks like a led bulb. The old wands will not work since they dont have the infrared tip. Kinda sucks that we have two older wands and we can't use them to make the spells work. I guess we are going to have to spend another $50 for an infrared wand. But it is a very cool interactive display. We have been to universal about 10 times since Diagon opened this year. I really liked Borgin & Burkes located in Knockturn alley. It's a really cool shop that specializes in the dark arts.

 

[mikeerdas]

Disney also uses a projection to create the ghost on the Tower of Terror. The ghost appear during the ride on your way up to the drop flloor. It looks like they still used the 45 degree angle to hide the projector. You can see the angle of the glass on the tile floor.

Thanks Sid. Missed this bit yesterday. Will definitely look for this next time I ride the Tower of Terror @ Disney's Hollywood Studios. I'm a huge fan of the original Rod Serling Twilight Zone series--wife bought me the box set a few years ago. Will have to look not only for the Pepper's Ghost effect, but also for the homages to various Twilight Zone episodes said to be dispersed throughout the ride. The Martin's Videos guy--who does the fantastic hour-long Haunted Mansion multi-angle attraction video (found on either Vimeo or YouTube) also has an Ultimate Tribute video on the Tower of Terror. I've not watched that one yet, but it's in my viewing queue.

 

[mikeerdas]

Yes. The wands are infrared. You can see the difference from the older wands compared to the newer wands. The newer wands have a reflective tip that looks like a led bulb. The old wands will not work since they dont have the infrared tip. Kinda sucks that we have two older wands and we can't use them to make the spells work. I guess we are going to have to spend another $50 for an infrared wand. But it is a very cool interactive display. We have been to universal about 10 times since Diagon opened this year. I really liked Borgin & Burkes located in Knockturn alley. It's a really cool shop that specializes in the dark arts.

Thanks so much Sinister Sid and CDW! Have to head out to work, but will check out the articles you referenced. So the infrared tip explains why people had been asking the wrong question: "how / where do you replace the battery" that I'd seen when I was searching the Internet several weeks ago.

Don't want to pay $40 to $50 for the wand. Anyone know the technical specs of the infrared reflective tip? Hell, I'll duct-tape or scotch-tape something to a cheaper, older wand if it will work. Would be a great hack. Would only need a source for the reflective material. Again, will check out the articles later today or this week.

Thanks again for the effect Reveal! This had been puzzling me. Did watch some very cool videos, however, last night on YouTube about the Kinect device. Search YouTube for phases like: how does the kinect work, and look for the ones where people have videoed rooms where a Kinect unit is active, using a night vision / infrared camera mode. And you'll see that the whole room, every object and every person in it, is draped with tiny infrared dots. Super-cool technology. Also saw hack videos where people have used the Kinect device to create 3D models of both people and objects.

While it's been some time since I've bought a video game console--I'm typically a Late Adopter, purchasing older consoles when new models arrive, and everyone's trying to dump the prior console version. Allows me to purchase used games cheap. Don't have as much time for gaming as I did before I had a full time job and mortgage... but I absolutely love re-purposing devices.

 

[CreepyCreations]

CDW's top image is EXACTLY how the effect is done in the Haunted Mansion. Because the props are either above or below the Doom Buggies, that provides the angles needed. You'll notice that no props appear level with the Doom Buggies because of this method.

 

[GobbyGruesome]

Just watched this interview (it's fun, but pretty rough around the edges) with Rolly Crump on youtube and he talks bit about the Pepper's Ghost effect. It's a 90 minute interview and it's in there somewhere.

He mentions at the end that they got a lot of ideas from an old book called The Boy Mechanic which is old enough to be on the Gutenberg Project...
http://www.gutenberg.org/files/12655/12655-pdf.pdf

If you jump to page 69 of that PDF, you can read the bit that inspired the mansion's Pepper's Ghosts. Not a lot to go on.

 

[mikeerdas]

Gobby, thanks for both the video and book link!

Just watched this interview (it's fun, but pretty rough around the edges) with Rolly Crump on youtube and he talks bit about the Pepper's Ghost effect. It's a 90 minute interview and it's in there somewhere.

He mentions at the end that they got a lot of ideas from an old book called The Boy Mechanic which is old enough to be on the Gutenberg Project...
http://www.gutenberg.org/files/12655/12655-pdf.pdf

If you jump to page 69 of that PDF, you can read the bit that inspired the mansion's Pepper's Ghosts. Not a lot to go on.

 

[mikeerdas]

Was watching another YT video on the Haunted Mansion last night. In it, at around 4 mins 10 secs, Rolly Crump picks up and shows the camera a spiral bound book by magician, illusionist, and author Jim Steinmeyer titled "The Science Behind the Ghost":

Well, I just had to dig deeper. Found a newer edition being sold. Seemingly pricey at $65 + $5 shipping; but magician's trade books are specialty items (not mass market publications); so the "high" price didn't surprise me. And this will be a fantastic addition to my home library. Ordered a copy just now because I'm endlessly fascinated by the effect. Steinmeyer is a good writer. And this seems to be the definitive history of the Pepper's Ghost effect. Nice for someone like me who wants more depth on the topic:

http://www.jimsteinmeyer.com/catalog/product.php?productid=17563

There's a great mass market book, and so much cheaper, by Steinmeyer titled Hiding the Elephant: How Magicians Invented the Impossible and Learned to Disappear that has some good material on Pepper's Ghost. Actually three chapters:

http://www.amazon.com/Hiding-Elephant-Magicians-Impossible-Disappear/dp/0786714018/ref=sr_1_1?s=books&ie=UTF8&qid=1410611201&sr=1-1&keywords=hiding+the+elephant

You can see a preview on books.google.com:

http://books.google.com/books?id=TnwDvCk3QdYC&printsec=frontcover&dq=hiding+the+elephant+pepper%27s+ghost&hl=en&sa=X&ei=ZTgUVOevDPDjsAThuoDIBQ&ved=0CCgQ6AEwAA#v=onepage&q=hiding%20the%20elephant%20pepper's%20ghost&f=false

Just watched this interview (it's fun, but pretty rough around the edges) with Rolly Crump on youtube and he talks bit about the Pepper's Ghost effect. It's a 90 minute interview and it's in there somewhere.

He mentions at the end that they got a lot of ideas from an old book called The Boy Mechanic which is old enough to be on the Gutenberg Project...
http://www.gutenberg.org/files/12655/12655-pdf.pdf

If you jump to page 69 of that PDF, you can read the bit that inspired the mansion's Pepper's Ghosts. Not a lot to go on.

 

[GobbyGruesome]

Very cool finds, Mike. I'll add 'em to the list. Let me know what you think of "The Science Behind the Ghost"