Introduction to 3D technology

3-D films have existed in some form since the 1950s, but had been largely relegated to a niche in the motion picture industry because of the costly hardware and processes required to produce and display a 3-D film, and the lack of a standardized format for all segments of the entertainment business.

People Watching 3-Dimensional Movie

HOW ARE 3D FILMS SHOT:

3D films requires:

1. Special cameras and rigs to shoot from two or more angles and to obtain images that can be combined to form a 3D image.
2. A complex understanding of the concept of depth and how human mind perceives it.
3. An empathizing of where and how the user will view the movie,and suitability of the images to his viewing positions.
4. Complex editing , and in some cases 2D-3D conversion tools,working with high performance computing platforms.
5. High level of skills to maintain parallax,vertical gap and the like.

FEW CAMERAS USED FOR 3D  SHOOTING

Panasonic 3D camera recorder(AG-3DA1):

Contains an easy to handle body that contains two lenses and automatic correction for horizontal and vertical displacement and image convergence which reduces the complexity.With Panasonic AG-3DA1, one could shoot over 15 different locations and cover 161 km in the same period of time.
         Panasonic has also launched a consumer level 3D camcorder(SDT750),which requires the user to add only a 3D conversion lens to automatically enable 3D shoots.Left and Right-eye images are simultaneously shot with two lenses and the camera creates 3D images by artificially reproducing visual diparity.

panasonic-ag-3da1-3d

 HOW IS 3D CONTENT BROADCASTED:

CONVENTIONAL METHOD:

The left and right HD images are multiplexed(either side by side,top and bottom or otherwise) into a single HD signal,which is decoded back into 3D by the viewer’s TV set.The user needs to have a 3D ready TV but no need of any special set-top box.

Disadvantages in this method:

• Since ethe two HD signals are compressed into one,the resultant 3D image loses up to half of it’s orginal resolution.
• The broadcast version can be viewed properly on 3D TV’s and is useless when seen on 2D set.Hence the operator would have to broadcast two versions(2D and 3D) versions of the same channel which makes it more expensive, bandwidth-intensive satellite transponders.

PERMANENT,EFFECTIVE AND LONG RUN METHOD:

Here the left-eye signal is broadcast as a standard MPEG picture,while the data for second eye is derived using the left as reference(also called 2D+Delta or 2D+Difference).Such a system would require new advanced decoders to be built in the set-top box.

This can also be seen normally on a conventional 2D set, without 3D experience and thereby relaxing the operators to broadcast two versions of the same channel.

OLD 3D GLASSES:

3D color googles

The 3D viewing was based on crude,coloured 3D glasses.These glasses are very much inexpensive and just around Rs 10 only.

The technique used by these old fashioned coloured 3D glasses are called COMPLEMENTARY COLOUR ANAGLYPHS. These used red and cyan lenses(or paper) to pass red to one eye and blue and green to other. This method was capable of working only with Black and White images.                                 

 But the latest methods allow for colour viewing as well,although the colour will be a bit dull.It is this colour loss that makes this technique inferior to others such as polarization, and also causes nausea and headache in some viewers.

2D-TO-3D CONVERSION:

There are hardware and software components available today that can be embedded in disk players,set-top boxes and even in televisions to enable the conversion of 2D content to 3D .
        It works by adding a dimension of depth to the content, doing the necessary splitting of images into seperate streams for each eye.However this is not that much effective.

 3D is not suited for all the contents.3D is best suited for contents such as slow panoramic shots.Hence a lot of jolting and crude transitions are introduced into the converted movie-which certainly doesn’t give a pleasant result.

The quality of the conversion is dependent on many factors ,ranging from the type of equipment on which it is going to telecast,making it a very unpredictable business.