Talk:Pepper's ghost/Archive 1

It was Leonardo who first described the camera obscura
not as claimed here.

Pepper's "Ghost" or "ghost"
Sorry to whine, but I really thought that this page should have been redirected to "Pepper's Ghost" (capital "G") rather than the other way around. I'm not sure that people are going to find this page since I would have expected to use a capital "G" instead of a lower case one. Thoughts? Bill 22:15, Mar 23, 2005 (UTC)
 * OK, I realize that the preferred capitalization is as indicated here. But I have another inconsistency. See below. --billlund 01:37, July 11, 2005 (UTC)

Dates of John Henry Pepper and the London Polytechnic Institute
I've confirmed in the reference listed on the main page that John Henry Pepper created this illusion in 1862. The London Polytechnic Institute (now the University of Westminster) was founded in 1838 by Sir George Cayley and later became the Polytechnic at Regent Street - 1881 - Quinton Hogg. I verified that too on the University of Westminster's web site. John Henry Pepper was in fact a professor of chemistry at the London Polytechnic, and that he originataed the illusion we're talking about here; however, since it appears he did that 19 years before the founding of the institute, I wonder what relationship there is between the illusion and the institute. I feel there is none, other than a coincidental association through John Pepper. It seems we should drop the reference to the institute. --billlund 01:37, July 11, 2005 (UTC)
 * Mea culpa... The institute was founded in 1938 and they in fact list John Henry Pepper on their history page. I'm adding this to the external links section.--billlund 01:40, July 11, 2005 (UTC)

For anyone who should come across this discussion page, I want to settle this discrepancy. According to Jim Steinmeyer in Hiding the Elephant (2003), The Royal Polytechnic first opened in 1838. This date is verified on the UV of Westminster website. With a degree in Chemistry, John Pepper joined as a lecturer in 1848. In 1854 he became the director and "sole lessee" of the institution. He first showed the illusion on December 24, 1862 in a scene during Charles Dickens's "The Haunted Man." His illusion was a modification on the patented Dirksian Phantasmagoria invented by Henry Dirks in the same year. Henry Dirks had tried to market the illusion to various theaters, and presented a model at the Royal Polytechnic, where it was discovered by Pepper. Most dismissed the concept because it required complete reconstruction of most theaters to work. Pepper modified the illusion so that it could be more easily incorporated into existing theaters, and hence made it successful. Though he tried to give credit to Dirks, popularity made the title "Pepper's Ghost" stick.Verdad 15:24, 18 February 2006 (UTC)

patented?
I wonder how it could be patented, if it's more than 140 years old? Samohyl Jan 05:06, 27 December 2005 (UTC)


 * I was wondering about that too. More information would be useful.  I've added citation needed to the claim.  dbenbenn | talk 07:11, 5 February 2006 (UTC)


 * It was registered with the patent office sometime in the last 140 years? The patent rights expire, but the patent is also a public disclosure of what was done. MMetro 09:44, 8 November 2007 (UTC)


 * You can patent an image projection _apparatus_ such as Musion's Eyeliner. Thus, that is a patent on how it was made, not the technique it uses. I can't comment on any Dirksian Phantasmagoria patent. Regards &#32;-- Steve -- (talk) 21:02, 29 August 2020 (UTC)

Technical explanation
The actual explanation of the technique is missing. One can only grasp its basics by looking at the pictures.


 * Mr. Wizard demonstrated a miniature version of the trick. It depends on internal reflection from the 45 degree angled glass. It's the same reason why you also see yourself reflected when looking out through a window at night when you're in a brightly lit room, and the secret of one way mirrors. MMetro 09:52, 8 November 2007 (UTC)

.......................................................


 * A) It is not "internal" reflection. It is simply 'partial' reflection off an un-silvered glass/clear-screen surface.


 * B) Your 'one way' mirrors are actually called "Two Way Mirrors" and are a different thing. Those are *partially silvered* so the bright room sees a normal silvered reflection.  However, the silvering is not full and lets some light through from the bright room into the dark room 'behind' the 'faux-mirrror'. This allows people in the dark room to see into the light room.
 * The dark room does not provide enough light for the person in the bright room to see through the partial silvering.
 * *TWO WAY* because is allows both a 'normal' reflection AND allows seeing through it... used TWO WAYS.


 * Because those are real, complete reflections, they have all the 3-D characteristics for our eye/brain to see them in full, real 3-D; just like from a normal mirror. Also, placing them the correct distance locates their image correctly into the 'real' scene.


 * C) The drawings are misleading. There should be only one table; the one BEHIND the angled glass. Only the things you see THROUGH the glass are the "real" ones.  All things reflected off the glass are the "ghost" illusion.  Regards &#32;-- Steve --  (talk) 20:37, 15 March 2019 (UTC)

Musion Eyeliner merge? Examples moved? No change?
This article and the Musion Eyeliner article seem to overlap a bit. It may makes sense to move the list of Musion Eyeliner examples here to that article instead. It may also make sense to merge that article into this one, although that article reads a bit like an ad for Musion Systems (perhaps that article could be significantly reduced then merged into this one). Not sure how to proceed, not changing anything. --24.190.217.35 (talk) 05:06, 2 January 2009 (UTC)


 * I was going to add e.g. Cheoptics360 and Musion Eyeliner to See-through display but it's not clear at the moment whether beamsplitter-based approaches meet the definition of "See-through display", so haven't done it yet. I don't know about moving the Eyeliner examples - just having a continually expanding list of examples seems a bit silly while a list of implementations would be neater and they can provide their own examples, but then I share your concerns about those pages becoming ads. Louis Knee (talk) 11:30, 28 June 2020 (UTC)


 * From the Wiki Musion Eyeliner description, it uses the Pepper's ghost technique. &#32;-- Steve -- (talk) 12:38, 28 June 2020 (UTC)


 * But, just adding ever more examples of every use will make this article ugly and turn it into an extended set of adverts, hence I added an intro paragraph to that section. Meanwhile, note that BASE Holograms (Whitney Houston; Holly and Orbison) deny they use Pepper's Ghost at all... Louis Knee (talk) 21:38, 28 August 2020 (UTC)

Toys using similar illusion effects?
I'm pretty sure that one of the old toys I had as a child (the Star Trek Transporter) used a similar method of making figures "disappear". Can anyone confirm this? --139.153.253.46 (talk) 14:28, 23 March 2010 (UTC)

Advertisement Style
The five Pepper's Ghost displays that have just recently opened in Dover Castle on the South Coast of Great Britain, have been meticulously engineered by Simon Beer of Integrated Circles. Because the visitors are so close to the illusions, hiding the mirrors and replay images became a priority. Getting the mirrors into position through the vaulted rooms of the Castle with just a 5 mm clearance was a major achievement. The result is a variety of close field, full-scale Pepper's ghosts that look stunning even if you know how they work. The close interaction by the ghosts, with the set, works particularly well in this mediaeval setting.

Dutch Igloo is a company based in the Netherlands that specializes in Pepper's ghost films. This company shows that Pepper's ghost films don't necessarily have to have a paranormal theme; they instead use the Pepper's Ghost technique to tell poetic stories. In Europe, the technique can be seen in the Dutch Railway museum in Utrecht, Holland. (in old travel trunks in a lost luggage installation in the railway station). New improvements for the Peppersghost experience are the real 3d experience in peppers ghost, to be seen in the Media Experience in Hilversum, Holland. Also new is the Peppers ghost film combined with an ordinary film projection, to be seen Kasteel Groeneveld, Baarn, Holland.

These two paragraphs sound very much like advertisements and may be subject to deletion. Should it be done?--Anon423 (talk) 05:54, 14 March 2011 (UTC)


 * I agree, and have removed them. 28bytes (talk) 06:08, 14 March 2011 (UTC)

Ghost-Table Images Correct?
I am wondering if the images used to explain the technique are correct. From the discription, it seems like only the ghost would be wanted in the hidden room, while the table should be only in the visible room. To the viewer, the table should appear real, while the ghost would appear ghostlike. The images don't seem to show this correctly, but I could be wrong. Jimaginator (talk) 17:45, 1 April 2011 (UTC)
 * Doing it that way requires that you be very careful with the lighting. Even if the ghost room doesn't have a table, it's still going to have the wall behind the table. If any light at all gets on that wall it will allow the viewer to see "through" the table making the table look ghostly. This would give away the trick. Better to make the two rooms identical if possible.  (Alternatively, the ghost room could be covered in very black, very non-glossy cloth, I'm not sure which works better in practice, but that'd be harder to illustrate.) APL (talk) 02:58, 7 November 2011 (UTC)


 * Not so in practice you must control the lighting. having two 'real' things requires precise alignment.  Duplicating a complete set is expensive and it is easy to do careful blocking (positioning) on a stage if necessary.  Been there, done that. &#32;-- Steve --  (talk) 20:42, 15 March 2019 (UTC)

Related: Gauss Ocular
There is a kind of ocular used in spectrometry in which a grid between the object and the eye is iluminated using a light bulb off axis and an oblique glass between the eye and the grid. The Pepper's ghost effect is also used in some home-made HUD systems. It wold be nice to write this in the article, but I don't know very well how to use wikipedia :( Thanks.--79.109.46.149 (talk) 17:56, 11 November 2011 (UTC)

New source
http://cambridgelibrarycollection.wordpress.com/2012/02/06/professor-pepper-and-his-ghost/

A good source for some more about Dircks and Pepper. violet/riga [talk] 13:21, 15 August 2012 (UTC)
 * Excellent violet/riga, I have added this to the References section. What is still needed is to perhaps write additional prose according to what appears in this article; please feel free. Prhartcom (talk) 19:45, 2 August 2015 (UTC)

In what way is the "Political speech world record" to do with the Pepper's ghost illusion?
Could someone explain why this example of video simulcast is in this article? Richwil (talk) 09:53, 16 April 2015 (UTC)
 * Richwil, the Pepper's ghost illusion is the inspiration for the technology that allows a "hologram" of Chief Minister Modi or Tupac to appear onstage. It is the same illusion except an image is projected onto stretched film rather than reflected onto glass. See the next comment below. Prhartcom (talk) 19:45, 2 August 2015 (UTC)

This isn't an article on unofficial world records for simultaneous use, though. That's like having the world's biggest drive-in listed as a factoid under "automobile." It's not really pertinent to the automobile itself. That this has been used by a government official to make virtual appearances at multiple locations is newsworthy, but there's no reason for this article to be keeping a running track of the number.

Holograms are not Pepper's Ghost
The Pepper's Ghost technique involves a partial mirror and secret room. The "holograms" used in concerts and the like (e.g. for Tupac at Coachella) involve the projection of an image onto a flat transparent screen of some sort. While the final results are similar, they're two entirely different techniques. I believe this misunderstanding started because the manufacturer of the projection equipment (AV Concepts) originally described their own technology as "using Peppers Ghost technology" (source), and media sources just took it as fact. They later changed it to say it's "based off of the Pepper’s Ghost illusion", and that they "updated it with 21st century technology" (source). In reality it's a related technique at best. 50.153.165.2 (talk) 10:00, 2 August 2015 (UTC)
 * Fair enough, and thanks for the source (although it is a primary, rather than secondary, source). At your suggestion and per the second source you provided, I have added the phrase "based on" to the concert section and added reference to the source. The word "hologram" is already in scare quotes and accompanied by the phrase "loosely marketed as". Prhartcom (talk) 17:22, 2 August 2015 (UTC)

Ivan used Pepper's ghost
Having done this, it is clear that there is least one. The slanted screen and large structure under/forward it, behind Ivan around 1:50 and other times, is very clear: https://www.youtube.com/watch?v=5bFO0dyXqsk &#32;-- Steve -- (talk) 19:50, 2 June 2019 (UTC)
 * It looks more like the related projection technology discussed above.
 * Pepper's ghost is usually meant to mean two separate live images merged. Not one live and one from a projector. ApLundell (talk) 18:55, 3 June 2019 (UTC)
 * I'm reporting something else. Actual projection onto a partially diffuse-reflecting screen or scrim (mentioned above) and simply a smooth-surface 3D depth preserving specular reflection are two different things.
 * One is a flat (gauze-like) ordinary-screen image that is typically lit in front to see the printing on it, then lit behind to show what's behind. The other provides a reflected image floating behind the 'screen' (as a mirror does), "two-way mirror-like". Understand?
 * The size of that box below the slanted screen suggests a screen, not a projector. Without more camera angles or being there I can't tell if that image is behind or on the screen.  So moot it is.
 * I've always considered Peppers Ghost as any partial glass-like (non diffuse) reflection / see-through, the same concept regardless of 'fake' image sources. It is completely the same concept of specular reflection. Regards, &#32;-- Steve -- (talk) 20:54, 3 June 2019 (UTC)