Expanding the field of vision enlarges the standard (human visual) 60-degree field of view to include more peripheral information and possibly reduce distortion. Techniques include using wide-angle lenses, adjusting the viewing distance, using AR smart glasses, and adopting a broader perspective.
Key Concepts in Expanding Vision
- Cone of Vision: The typical viewing area is around 60 degrees; the distance from the object expands the view.
- Technological Expansion: Devices like SpiderVision and AR glasses capture wider fields of view with rear-view cameras for enhanced peripheral information.
- Ophthalmology: Peripheral prisms and AR tech help manage visual field loss by shifting hidden information into the central view.
- Art: Techniques like anamorphic projections can enhance spatial perception beyond the standard view.
- Psychology: “Zooming out” offers a broader perspective for better understanding complex situations
Advantages - Increased Information Processing: A broader perspective enhances spatial awareness but demands greater cognitive effort.
- Distortion Management: Expanding beyond a 60-degree field can increase distortion, depending upon which type of perspective view/image is used, akin to a wide-angle lens.
- Improved Mobility: Wider simulated views enhance distance perception in navigation.
Expanding the Field of Vision
A fundamental feature of all perspective methods/instruments/systems is the concept of field of view (FOV), which, for an outward-looking optical instrument, is a measure of the proportion of the total environment (180°/360°) captured in a single perspective image taken from a particular viewpoint. Often, we relate such images to the natural monocular FOV of the human eye—known to be around 135 degrees horizontally (HFOV) and 180 degrees vertically (VFOV)—whereas the Binocular FOV is around 114 degrees horizontally.
Over the centuries, there have been attempts to go beyond these limitations in natural vision, specifically to facilitate viewing, matching/modelling, and representation of spatial reality. Artists have explored cylindrical and spherical surfaces to depict their paintings across a wider FOV.
In the 20th-century, photography has contributed to these developments. A wide range of lenses were produced, from extreme wide angle (84°-179°) to wide angle (63°-83°), normal (34°-62°), medium telephoto (24°-33°), telephoto (8°-23°), and super-telephoto (4°-7°). Wide-field developments occurred on three fronts: fisheye, multi-camera (polydioptric), and catadioptric cameras. In the open air, without refraction, there are 180 degrees; as in a fisheye, or through multiple cameras in a dome, we can compress spatial reality to capture/represent up to 360 degrees for a total view of the environment.
A second front lay in the development of multiple (or poly-dioptric) cameras. Simple versions typically use symmetrical numbers, such as 2, 4, or 8 cameras, resulting in cylindrical panoramic images. These methods have been complemented by spherical configurations such as the Google Street View and related cameras, leading to ever more dramatic omnidirectional perspective images.
The third front lies in catadioptric lenses, which typically involve mirrors: parabolic, hyperbolic, elliptical, or planar. These principles are applied to omnidirectional perspective images, which can subsequently be converted into cylindrical panoramic images. In addition to the original scene’s shape (visual field) and the recorded scene’s shape (visual image), there is the question of the projected surface (or display surface), which can range from a shallow/ deep concave bowl to a full hemispherical or full spherical dome, which can in turn entail its interior or exterior surface.
In sum, panoramic perspectives remain popular, as we seek to match/expand the natural visual field.
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