Research
Stereoscopic 3D
|What is Stereoscopic 3D?
|Stereoscopic 3D myth-busting fact No1
|Stereoscopic 3D myth-busting fact No2
|Stereoscopic 3D myth-busting fact No3|
Stereoscopic 3D
Solent Productions have been heavily involved within investigative research that focusses on the growing
3D film and broadcast industry. As Sky 3D ramp up their 3D output by increasing their production facilities,
the broadcaster recently announced that more 3D events will be undertaken in the future. This includes the
first ever live 3D music festival at this summer's Isle of Wight through Sky Arts:
Sky to broadcast Isle of Wight Festival live and in 3D
www.isleofwightfestival.com|
Sony Builds 3D Outside Broadcast Trucks as 3D is taken to New Sports and the Arts www.sony.co.uk|
Other examples of innovative 3D output from Sky 3D include the upcoming Champions League Final
which is being shown in a large number of pubs in the UK as well as Flying Monsters 3D, which is a groundbreaking documentary featuring David Attenborough that is also being shown in 3D cinemas.
With some very basic 3D production facilities now at Solent including a mirror rig, 3DTV and onset
stereoscopic monitoring, we are interested in hearing your thoughts, interests and any contributions
that you may be able to bring to the table regarding 3D tests and productions.
Solent Productions are looking to hold a series of 3D workshops on the Solent campus for interested
Solent students and staff members that are keen on discovering more about the medium. The workshops
will focus on the theoretical fundamentals of stereoscopic 3D including pre-production, shooting stereo
and editing stereo.
Consideration and understanding of 3D impacts a whole plethora of departments ranging screenwriting,
motion graphics, 3D animation, cinematography, engineering, editing and distribution so we are keen to register interest from parties from a variety of fields.
To register your interest, please contact: craig.lees@solent.ac.uk|
What is Stereoscopic 3D?
Stereoscopic 3D involves replicating depth perception that we acquire through human binocular vision and the image disparities produced between our left and right eyes. We call it stereoscopic as it involves two viewpoints or perspectives, like with audio in the manner in which stereo sound works. The term stereoscopic 3D, or S3D for short, is used to differentiate it from the 3D world which is historically more associated with the realms of 3D modelling, CGI and visual special effects.
Stereoscopic 3D myth-busting fact No1
Shooting 3D, you just stick two cameras together right?
Well, yes, you can, but this encroaches serious limitations regarding the level of creative control being imposed upon the images that you aim to capture. And Stereo 3D is very much a creative tool! We want to use depth perception to enhance our story!
3D cinematography requires a new set of rules in relation to image acquisition. One major consideration is the nearest distance of the framed scene's subject material as it has a huge influence upon the amount of 3D volume achieved in the scene. Other factors include focal length, distance between the centre of the two lenses of the camera (known as inter-axial distance) and the cameras' sensor size.
These stereoscopic parameters are detriment to filming good S3D as there are obvious limits upon how much bad 3D can be fixed in post. Getting it right in camera to begin with is imperative!
For example, there is a very rough rule based on a wide angle lens and a TV sceen output which is called the 1/30th rule of 3D cinematography.
This rule states that the distance between the two centres of the lenses (inter-axial) should be 1/30th the size of the nearest subject/object in your scene.
i.e: You are filming an interview and the interviewee's knees are the nearest thing in your scene. The closest inter-axial distance you can achieve by mounting the little bodies of your HD handycams together in the side-by-side position is 70mm. The very closest the knee can be positioned to the camera is 2.1 metres (2100mm).
Variables that will influence this nearest distance include sensor size, screen display size, lens focal length and age of audience (children's eyes are closer together and not so susceptible to the capacity of fusing together the large volume stereoscopic imagery that adults can).
There are many things to consider in shooting stereo imagery, for example:
-
Camera synchronisation - the shutters of each camera must be in sync so that each camera (or each eye) is recording exactly the same image in the exactly same place in time. One of the best methods to achieve this is using the Genlock function of cameras.
-
Lens synchonisation and callibration - zoom wander errors and matched 3D lenses.
-
3D sound - utilising 5.1 and 7.1 sourround sound.
-
Solutions for Live on set/on location 3D monitoring - being able to previsualise the 3D on set.
-
Depth of field - shallow depth of field does work in 3D, just watch Tron Legacy, but it may not be the effect that you want, say 3D sports for example.
-
Depth budget - How much '3dness' do we want the scene to contain?
-
Depth script - How does our script best make the use of 3D in each scene to tell a convincing 3D story?
-
What size screen is this going to be shown on and how will people view it in 3D?
Stereoscopic 3D myth-busting fact No2
You can't zoom-in within 3D?
With the right system, you can. Has anyone watched the Sky 3D football in the pubs? The 3ality system as used by Outside Broadcast company Telegenic offers the ability to zoom should the action be required. But what must be noted is that the amount of perceived 3D depth dramatically increases depending on the amount of 'zooming-in' applied to the cameras' focal lengths. The 3ality Stereoscopic Image Processor (or SIP) tells the 3D rig that the inter-axial distance needs to be reduced to accomodate for the change in the longer focal length. By compacting the frame, the image magnification means that the difference between the two sets of images grows considerably and hence increases the amount of 3D depth. The 3ality SIP applies the corresponding motorised geometrical alignments mechanically to the cameras so that the acquired 3D depth remains intact for the scene. Sony's MPE-200 '3D box' does much the same except it makes the geometrical alignments digitally as opposed to applying the geometrical fixes via motorised mechanics to the cameras themselves (as well as being able to do a whole plethora of other exciting things).
This is how live 3D is able to be carried out successfully.
The 3ality system:
www.3alitydigital.com/3flex|
The Sony system:
www.sony.co.uk/biz/content/name/dw-3d-liveproduction-0410|
Stereoscopic 3D myth-busting fact No3
Why do I have to wear those annoying glasses to see 3D?
Why can't manufacturers just makes glasses-free 3D screens like the Nintendo 3DS?
Glasses-free 3D (or what is known as auto-stereoscopic 3D) on the bigger scale is still very much in its infancy. Toshiba have already released a 20" version based on the same parallax-barrier technology as the Nintendo 3DS. The viewing experience of these early systems can be altogether rather limiting as the screens have a number of sweet-spots where the 3D experience is optimal with the effect being largely reduced when deviating your head from this sweetspot. Also with these early glasses-free prodcuts, the bigger the screensize, the more resolution is lost which also has a huge effect upon the 3D experience.
We will continue to use glasses for some time but the parallallax barrier technology has some legs, unlike the much older lenticular screen technology and it will be interesting to see what products Toshiba and the like come up with over the next few years.