Three Dimensional Cinematography

Abstract

Recent Developments in computer vision and computer graphics, especially in areas of  multiple view geometry and  image  based  rendering,  are  making  it  possible to  generate  3d  models  of  dynamic  scenes  from  multiple cameras  with  high  video  frame  rates.  The  process  is  named  as  a  three  dimensional  cinematography  (orbinocular cinematography) since  it  extends traditional cinematography  (2D)  to 3D at  the same frame rate.  A three dimensional (3D) cinematography is a motion  picture that enhances  the illusion  of  depth perception. 

 A special  motion  picture  camera  is  used  to  record  the  images  as  seen  from  two  perspectives  (or  computer generated  imagery generates  the  two  perspectives).  Special  projection  hardware  and/or  eyewear are  used  to provide the illusion of  depth  while  viewing.  This  technology is  used  in  both theatrical  releases  and television broadcasts.

The  editing  of such  movies leads  to a  variety of novel challenges.  But referring  to  the  “PC Quest”  magazine (dated march 03, 2010) this paper describes some interesting tips and tricks for creating your own 3-D movie with the help  of two separate digital cameras (not  described in  any of  the paper  yet). It includes all the  basic requirements to have a clear overview of 3D and hence the line “All about 3D movies”.

  

1.Introduction

Cinematography is all about feeling, exper ience, and identification with characters. Moreover it is a technical trick. As 3-D is a natural way of viewing, it brings a feeling of realism to the audience. With 3-D, we no longer  have to rebuild the volume of objects in the scene we are looking at, because we get them directly from our visual system. When it comes to close-ups, the effect is even stronger. When it comes to landscape shots, a majestic view is produced in front of the eyes with roundness and volume. Since your eyes are two inches apart, they see the same picture from slightly differ ent angles. Your brain  then correlates  these two images  in order to  gauge  distance. Thus to generate  a real 3-D view in front of you, this technology uses two light rays for projection. To separate these two rays, we require Polaroid glasses. If the film is viewed without the glasses, it will be a very strange sight since you cannot make it out the difference in the two views.

Since the late 19 century, pioneer s in 3-D movie making have given the public an interesting th way of viewing motion pictures. From the groundwork in still-image stereoscopy laid in 1840 to the latest 3-D blockbusters, the third dimension has always captured the imagination of the masses. Phil  McNally, alias “Captain 3-D” and a global stereoscopic super visor  teaches stereoscopic 3-D to hundreds of artists  who  have  already  mastered animation 3-D.  After  many  years of producing 3-D movies, he says: “One can teach the whole theory of stereoscopy in two hours. You can  learn all about 3-D movie-making in two  months. That will never give you the 10 years  of experience  needed to  master  it. Good  movies  are  made with experience,  not  with knowledge”.

2. History of 3-D movies:

Since  it’s invention in 1838, stereoscopy has  been used  as a technique to create the illusion  of   a  third  dimens ion.  The  fir st  3D  film  was  “L arrivee  du train”  by Lumiere brothers, the invent or  of cinema referred to as the first  stereoscopic movie ever   made.  When  it  was  releas ed,  audiences  panicked  becaus e  they  thought   thetr ain was about to crash into them!.

2.1:  

1950 to 1960: The first golden age:

  During this decade, the first boom of  3D  was observed. But here 3D  fell out of use because of  the poor  viewing conditions  in most of  the theatres and due to complex equipment required to exhibit 3D movies .

2.2:   

1986 to 2000:  The revolu tion:

 With  the  invention  of   IM AX  3D   format,  the  emer gence  of   new  screening technology  finally  comes   into  its own. Although  3D  was  used  only  in specialized productions due to t he prohibitives hoot ing costs, it took its rightful place.

2.3:

 2001 to t oday:   Second Golden age:

 The  advent   of  computer   animat ion  technology,  digital  camer as  and  3D  home theatr e contr ibute to the democratization of stereoscopic production and screening. The  demand  for  3D  continues  to  grow  and  the  technology  has  now  entered  its second golden age.

3.Basic concep ts required in understanding 3D

There  are  two  basic  ideas  in  under standing  the  main  log  involved  in  3D cine matogr aphy.

1.       Conver gence
2.      Ster eoscopic vis ion

3.1 Convergence

When an object is at  a great distance, lines of  fixat ion to t he object  f rom a viewers separ ate  eyes   ar e  near ly  parallel.  When  the  object   is  near,  t he  viewers  eyes  are turned  towar ds  the  object   and  the  fixat ion  lines  conver ge  at  a  more  noticeable angle. If  a  per son  fixates  his  eye  on his  finger   at  arms  lengt h  and then  moves  his f ingers  tow ards his  nose w hile  maintaining the fixation in with eyes ,  the  eyes will “cross”. This  crossing of  the eyes is  detectable  by t he  sens ory/ control system that contr ols the position of the eyeballs  and produces a sens at ion of more depth or  less depth  accor ding  to  the  size  of   the  convergence  angle  of  the  eyes.  A  much  more important result of conver gence  is that it  also ser ves to place the two right and left  eye  images   of  the  object   fixated  upon  at  the  corresponding  retinal  point s  in  the centr al retinal area of each eye, thus  allowing binocular  fusion to take place.

3.2 Stereoscopic vision

When  a  person  looks   at  an  object, the  retinal  image  in  the  right  eye  is   different  from  the retinal  image in the left  eye. This  difference is the result  of the two eyes viewing the  object  from two  slightly  different  positions .  Experiments  have shown that the human visual perception system is  highly sensitive to the difference in the two retinal images.  The visual perception system uses the amount of disparity as  a measure  of  the  depth  of  the  object  being  viewed,  with  increasing  disparity  being perceived as the object being closer. No disparity is perceived for  a far  background object.  The  convergence  and  spect oscopic  view   by  the  left  and  right  eye  of   the obsrver.

Advantages of 3D movies over ordinary 2D

Are 3D movies better than 2D ones?  Of  course they are. The main  difference  between the two  is  that-  with  a 2D  movie,  it  would seem as  if  you are  only  watching through a  glass, „viewing a world through a transparent window . However, with 3D movies you would feel as  if  something  is  pulling  you  towards  the  scene,  making  you  a  part  of  it  and  not  just  a viewer. These movies  make  use  of our  depth per ception to give us  the  maximum  viewing pleasur e. Depending on the depth, we may view something as flat and planar, or it can also look full and white volume. 3D  movies  allow  a  person  to  be  more  engr ossed  in  the  movie  because  of  the  details  the person views in  his  peripheral  vision. This enters into the subconscious mind  and enhances the experience, much as ordinary things that passes us by in our everyday lives. This makes the experience  more  real to us  than other  ordinar y  films. Nowadays  the  evolution  of three dimensional televisions has contributed a lot to the 3D generation. Figure 8: LCD televisions with original 3D experience

Conclusion

3D  cinematography  is  all  about  feeling,  exper iencing  and  identification  of  the  characters. Since 3D is a real way of watching, it brings a feeling of realism to the audience. With 3D, we no longer have to rebuild the volume of objects in the scene we ar e looking at, because we get them directly from our visual system. By reducing the effort involved in the suspension of disbelief, we signif icantly incr ease the immersion experience. But when  it  comes  to  landscape  shots,  the  effect  is  a  mixed  bag,  because  of  optical  laws there s a maximum size of what can be shown in a theatre, and it s not more than the screen size. Until we have the movie projected directly onto our eyeballs, we cannot view a picture bigger than the screen we look at. As a result, a majestic landscape placed beyond the screen will look big and flat. The  3D  version  of  latest  blockbuster  „Avatar   by  James  Cameron  has  created  a  great revolution  in  the  present  3D  world.  It  proves  that  the  field  of  3D  cinematogr aphy  is evergreen.