Editing Holography (section)

==False holograms==
[[File:Pyramid_holographic_3D_holographic_projection_phone_projector_3D_holographic_projection_3D_mobile_phone_naked_eye_3D_pyramid.jpg|thumb|A [[Pepper's ghost]] illusion made from a clear plastic [[frustum]]]]

[[File:Hatsune Miku - Tell Your World (Live @ Anime Friends 2017).webm|thumb|Shows making using of projected images are erroneously marketed as "holographic".]]

There are many optical effects that are falsely confused with holography, such as the effects produced by [[lenticular printing]], the [[Pepper's ghost]] illusion (or modern variants such as the [[Musion Eyeliner]]), [[tomography]] and [[volumetric displays]].<ref>{{cite news|url=https://www.bbc.co.uk/news/business-12328160 |title=Holographic announcers at Luton airport |publisher=BBC News |date=2011-01-31 |access-date=2012-04-21}}</ref><ref>{{cite web|last=Farivar |first=Cyrus |url=https://arstechnica.com/science/news/2012/04/tupac-hologram-merely-pretty-cool-optical-illusion.ars |title=Tupac "hologram" merely pretty cool optical illusion |publisher=Ars Technica |date=2012-04-16 |access-date=2012-04-21}}</ref> Such illusions have been called "fauxlography".<ref>{{cite web |url=https://light2015blog.org/2015/09/28/holographic-3d-technology-from-sci-fi-fantasy-to-engineering-reality/ |title=Holographic 3D Technology: From Sci-fi Fantasy to Engineering Reality |date=2015-09-28 |website=International Year of Light Blog |archive-url=https://web.archive.org/web/20171030003249/https://light2015blog.org/2015/09/28/holographic-3d-technology-from-sci-fi-fantasy-to-engineering-reality/ |archive-date=2017-10-30}}</ref><ref>{{cite thesis |type=MFA |last=Gordon |first=Marcus A. |date=2017 |title=Habitat 44º |publisher=OCAD University |doi-access=free |doi=10.13140/RG.2.2.30421.88802}}</ref>

The Pepper's ghost technique, being the easiest to implement of these methods, is most prevalent in 3D displays that claim to be (or are referred to as) "holographic". While the original illusion, used in theater, involved actual physical objects and persons, located offstage, modern variants replace the source object with a digital screen, which displays imagery generated with [[3D computer graphics]] to provide the necessary [[depth perception|depth cues]]. The reflection, which seems to float mid-air, is still flat however, thus less realistic than if an actual 3D object was being reflected.

Examples of this digital version of Pepper's ghost illusion include the [[Gorillaz]] performances in the [[2005 MTV Europe Music Awards#Performances|2005 MTV Europe Music Awards]] and the [[48th Grammy Awards#Performances|48th Grammy Awards]]; and [[Tupac Shakur]]'s virtual performance at [[Coachella Valley Music and Arts Festival]] in 2012, rapping alongside [[Snoop Dogg]] during his set with [[Dr. Dre]].<ref>{{cite news|url=http://marquee.blogs.cnn.com/2012/04/16/tupac-returns-as-a-hologram-at-coachella/ |title=Tupac returns as a hologram at Coachella |work=The Marquee Blog |publisher=CNN Blogs |first1=Carolyn |last1=Sung |first2=Topher |last2=Gauk-Roger |first3=Denise |last3=Quan |first4=Jessica |last4=Iavazzi |date= 16 April 2012|access-date=2012-04-21 |url-status=dead |archive-url=https://web.archive.org/web/20120504172454/http://marquee.blogs.cnn.com/2012/04/16/tupac-returns-as-a-hologram-at-coachella/ |archive-date= May 4, 2012 }}</ref> Digital avatars of the Swedish supergroup [[ABBA]] were displayed on stage in May 2022.<ref>{{cite news |last1=Brause |last2=Mills |title=Super Trouper: ABBA returns to stage as virtual avatars for London gigs |url=https://www.reuters.com/lifestyle/super-trouper-abba-returns-stage-virtual-avatars-london-gigs-2022-05-26/ |date=27 May 2022 |work=Reuters |access-date=4 June 2022}}</ref> The ABBA performance used technology that was an updated version of Pepper's Ghost created by [[Industrial Light & Magic]].<ref>{{cite web |title=ABBA's mysterious "Abbatars" revealed |url=https://www.graphicnews.com/en/pages/38425/entertainment-abbas-mysterious-abbatars-revealed-1 |first1=Ninian |last1=Carter |date=November 27, 2018 |website=Graphic News |access-date=4 June 2022}}</ref> American rock group [[Kiss (band)|KISS]] unveiled similar digital avatars in December 2023 to tour in their place at the conclusion of the [[End of the Road World Tour]] using the same Pepper's Ghost technology as the ABBA avatars.<ref>{{cite news |last1=Amorosi |first1=A. D. |title=KISS Says Farewell at Madison Square Garden, Before Passing the Torch to Band's Avatar Successors: Concert Review |url=https://variety.com/2023/music/concert-reviews/kiss-final-concert-review-madison-square-garden-avatars-1235819744/ |access-date=3 December 2023 |work=[[Variety (magazine)|Variety]] |date=3 December 2023}}</ref>

An even simpler illusion can be created by [[Video projector|rear-projecting]] realistic images into semi-transparent screens. The rear projection is necessary because otherwise the semi-transparency of the screen would allow the background to be illuminated by the projection, which would break the illusion.

[[Crypton Future Media]], a music software company that produced [[Hatsune Miku]],<ref>{{cite web|url=http://www.crypton.co.jp/mp/pages/prod/vocaloid/ |script-title=ja:クリプトン |title=Crypton |publisher=Crypton.co.jp |language=ja |access-date=2012-04-21}}</ref> one of many [[Vocaloid]] singing synthesizer applications, has produced concerts that have Miku, along with other Crypton Vocaloids, performing on stage as "holographic" characters. These concerts use rear projection onto a semi-transparent DILAD screen<ref>{{cite web |last = G. |first = Adrian |title = LA's Anime Expo hosting Hatsune Miku's first US live performance on 2 July |url = http://www.kawaiikakkoiisugoi.com/2011/06/16/las-anime-expo-hosting-hatsune-mikus-first-us-live-performance-on-july-2nd/ |access-date = 20 April 2012 |archive-date = 18 October 2012 |archive-url = https://web.archive.org/web/20121018154249/http://www.kawaiikakkoiisugoi.com/2011/06/16/las-anime-expo-hosting-hatsune-mikus-first-us-live-performance-on-july-2nd/ |url-status = dead }}</ref><ref>{{cite web|url=https://www.youtube.com/watch?v=ZCYJu7KSqQM | archive-url=https://ghostarchive.org/varchive/youtube/20211030/ZCYJu7KSqQM| archive-date=2021-10-30|title="We can invite Hatsune Miku in my room!", Part 2 (video) |publisher=Youtube.com |date=2011-09-07 |access-date=2012-04-21}}{{cbignore}}</ref> to achieve its "holographic" effect.<ref>{{cite web |title = Technically incorrect: Tomorrow's Miley Cyrus? A hologram live in concert! |url = http://news.cnet.com/8301-17852_3-20022743-71.html |access-date = 29 April 2011 }}</ref><ref>{{cite web |title = Hatsune Miku – World is Mine Live in HD |website = [[YouTube]]|url = https://www.youtube.com/watch?v=DTXO7KGHtjI |access-date = 29 April 2011 }}</ref>

In 2011, in Beijing, apparel company [[Burberry]] produced the "Burberry Prorsum Autumn/Winter 2011 Hologram Runway Show", which included life size 2-D projections of models. The company's own video<ref>{{cite web|url=https://www.youtube.com/watch?v=9t5dCIuz2wY | archive-url=https://web.archive.org/web/20111004055249/http://www.youtube.com/watch?v=9t5dCIuz2wY&gl=US&hl=en&amp;has_verified=1| archive-date=2011-10-04|title=Burberry Beijing – Full Show |publisher=Youtube.com |access-date=2012-04-21}}</ref> shows several centered and off-center shots of the main 2-dimensional projection screen, the latter revealing the flatness of the virtual models. The claim that holography was used was reported as fact in the trade media.<ref>{{cite web |url = http://www.vogue.it/en/shows/fashion-events/2011/04/burberry-in-china |title = Burberry lands in China |access-date = 14 June 2011 }}</ref>

In [[Madrid]], on 10 April 2015, a public visual presentation called "Hologramas por la Libertad" (Holograms for Liberty), featuring a ghostly virtual crowd of demonstrators, was used to protest a new Spanish law that prohibits citizens from demonstrating in public places. Although widely called a "hologram protest" in news reports,<ref>{{cite web |url=http://revolution-news.com/first-hologram-protest-in-history-held-against-spains-gag-law/ |title=First Hologram Protest in History Held Against Spain's Gag Law |publisher=revolution-news.com |access-date=2015-04-13 |url-status=dead |archive-url=https://web.archive.org/web/20150413044945/http://revolution-news.com/first-hologram-protest-in-history-held-against-spains-gag-law/ |archive-date=13 April 2015}}</ref> no actual holography was involved – it was yet another technologically updated variant of the Pepper's ghost illusion.

Holography is distinct from [[specular holography]] which is a technique for making three-dimensional images by controlling the motion of specularities on a two-dimensional surface.<ref>{{cite web |url=http://www.zintaglio.com/how.html |title=specular holography: how |publisher=Zintaglio.com |access-date=2012-04-21}}</ref> It works by reflectively or refractively manipulating bundles of light rays, not by using interference and diffraction.