We have seen so far what the origins of immersive photography are, so let's define the attributes as characterizing the nature of the medium:
Being photographic
Being panoramic
The need for an apparatus to be able to be viewed
Being interactive
To understand its "photographic" nature, let's make a comparative analysis with other classic mediums such as the static image, that is, with photography and the moving image, film or video.
To do this, we take common factors, or rather the basic characteristics that identify a medium of visual communication and which, although varying, are common to all:
The point of view
The shooting position in space, the point where the photo / video camera is located.
The angle of view
The portion of space represented, defined as the corner of the circle arc surrounding the photo / video camera.
The framing
The geometric structure, generally quadrilateral, which delimits the portion of space represented.
Time
Time is intended as a sequence of events, equivalent to individual images.
THE PHOTOGRAPHIC
In immersive photography, angle of view and framing are defined by the user, not by the photographer.
A photograph with a 360°x180° angle of view captures a scene from a predetermined point of view but, by definition, does not "cut out" a portion of the space.
It is a photographic type image, but without framing.
The viewer (software for viewing panoramic photos) interactively returns what the user defines by varying the angle of view and the framing.
So you have the vision of a photographic type image with a variable framing.
Time in panoramic photography can be "co-present", that is, the image is made up of several stitched photos, but taken at different times, even if for a few tenths of a second.
Modern 360° cameras (Theta, Samsung 360, etc.) or multi-camera systems report time synchronization, even if in reality there are two (or more) photos joined together.
THE PANORAMIC
Immersive photography is the transposition into the digital age of the original idea of the Panorama; the vision aroun us.
Generally the immersive effect comes to be complete with the possibility of viewing spherical scenes, therefore 360° x 180°, but the idea of the panoramic is already with cylindrical images, where the horizontal 360° correspond to much less than the 180° vertical.
And also there is a first immersion effect with images made with a simple fisheye shot.
However, the latter all have limits, only in the spherical scene there is no solution of continuity.
THE APPARATUS
For comparison:
Photography: Classical photography does not need a specific device to be able to be visualized: light is enough!
Film / Video: The movie needs an apparatus, the projector, to be able to be seen. Without this apparatus, it's nothing else than a sequence of photographic images.
Immersive Photography: The computer with the monitor and the software are the apparatus for viewing the immersive photography. Without this device it is simply a panorama with 360° of the angle of view.
The apparatus for immersive photography are now very different: the hardware part includes classic computers (desktops) as well as tablets, smart phones, or systems for VR (Playstation VR, Samsung VR, Oculus, etc. ).
Each one needs software that runs on their respective operating system.
This involves major problems on adaptability and possibility of a correct vision on all these devices.
INTERACTIVITY
Interactivity is a fundamental character of immersive photography: without interactivity it can appear as a simple photograph, or as a movie.
This content requires HTML5/CSS3, WebGL, or Adobe Flash Player Version 9 or higher.
THE POINT OF VIEW
Not having to frame a scene, the operation of the immersive photographer is mainly in choosing the point of view, as well as choosing the right moment to take it.(1)
Immersive photography leads to overcoming the framing, leaving it to the user.
Additional specific features of immersive photography:
SECONDARY INTERACTIVITY
Inside a panorama, in addition to being able to rotate and zoom in the view (primary interactivity), other forms of interactivity are possible, which I call secondary, but no less important for this.
Hotspots (sensitive areas) that allows to switch from one panorama to another (2), commands to open information windows about the place or the object being viewed, commands to view the position of the panorama on a map, are all elements that enrich the panoramas with content and transform them from a simple perceptual experience into an experience of knowledge.
MULTIMEDIA ADDITIONS
The digital nature of the viewers allow to insert further multimedia elements within the panoramas.
Sounds, films, moving objects increase the cognitive experience of the medium.
THE INFORMATION
A photographic image, the more defined it is and the wider its field of view, the more it transmits information about a scene or a place.
Immersive photography, with its characteristic of capturing everything around a place, has more information than a classic photograph, which takes up only one portion of the space.
This makes it the tool of excellence in the documentation of a place.
Google Street View, now widespread all over the planet, is the greatest demonstration of this.
Note that we are talking about quantity of information, not quality of information or interpretation.
OBSOLESCENCE
Since few years from its birth, immersive photography shows a weakness precisely in the reproduction system, the viewer, the software part of the apparatus.
In the great and tumultuous race of computer science, the viewer quickly becomes obsolete, in the sense that operating systems and browsers no longer support it.
Let's see how the QTVR viewer (QuickTime VR, the first immersive photography viewer, developed by Apple) is replaced by the Flash viewer (from Macromedia first and then from Adobe), and how in turn this is replaced by HTML5 code (evolution of HTML).
In the middle, other viewers are developed such as the one in Java, which first reproduces spherical panoramas in 2000 (3), and the viewer in Shockwave, Director's web output, a popular program up to the beginning of 2000 to compile multimedia CDs.
Today it is very complicated to reproduce an immersive photograph encoded in QTVR: old operating systems are required which in turn must be installed in old hardware often out of the market or difficult to find.
Obviously, at the base of every immersive photograph there is a flat panorama, in equirectangular projection (but even it, coded in TIFF or JPG, it is not guaranteed that it will be easily readable in the future) and that the algorithms to display it in the form of immersive photograph will always be there.
But all part of secondary interactivity can be lost, with the consequence that even simple virtual tours vanish.
Note:
1) Perhaps because of the greater amount of information, solutions have been sought to raise the point of view, with very high stands, poles, kites and drones. The vision from above emphasizes the concept of "panoramic" and increases the amount of information to the nadir. 2) The connection (link) of several panoramas (also called nodes) makes up a Virtual Tour. 3) Until about 2003, QuickTime VR could only display cylindrical panoramas.
