Housing

From Night Vision Wiki

This wiki currently differentiates the following housing types: Bi-ocular, Binocular, Monocular, Scope, Panoramic, Panoramic Binocular.

A diagram depicting the image seen with bioculars, monocular and binoculars

Monocular

A monocular housing consists of one objective lens, one image intensifier, and one eyepiece. It is worn in front of one eye.

Advantages

  • Least expensive
  • Lowest weight
  • One eye free[Note 1]

Disadvantages

  • No depth perception
  • Potential discomfort from mismatch between eyes

Housings

The following monocular housings have been documented on this wiki:

Bi-ocular

A bi-ocular housing consist of one objective lens, one image intensifier, a beam splitter, and two eyepieces. It is worn in front of both eyes, however providing no depth perception to the user.

Advantages

  • Less expensive than binocular devices (only one image intensifier)
  • Less discomfort than monocular devices

Disadvantages

  • No depth perception
  • Dimmer image than other types
    • Light from phosphor screen is split onto the two eyepieces
    • Inherent loss of light from use of mirrors

Housings

The following bi-ocular housings have been documented on this wiki:

Binocular

A binocular housing consists of a bridge (sometimes with articulation) connected to two pods. Each pod consists of one objective lens, one image intensifier, and one eyepiece. It is worn in front of both eyes and provides the most natural viewing experience with full depth perception to the user.

Advantages

  • Full depth perception
  • Less perceived image noise due to separate image intensifiers for each eye
  • Possibility to focus each eye onto different distances at the same time

Disadvantages

  • More expensive than monocular or bi-ocular devices (more optical components, two image intensifiers)
  • Heavier than monocular and some bi-ocular devices
  • Imperfections in lenses and image intensifiers more noticeable

Housings

The following binocular housings have been documented on this wiki:

Panoramic

A true panoramic housing features two fused pods per eye, with one pod pointing forward, and an additional pod pointing sideways at an angle. As such, each side of the housing produces a field of view of two partially overlapping circles. For the user, this means that one half of this shape on one eye will overlap with the other half on the opposite eye, forming one shared field of view with full depth perception, with an additional peripheral field of vision on the left side for the left eye, and on the right side for the right eye.

Advantages

  • All advantages of binocular housings
  • Additional peripheral field of view

Disadvantages

  • All disadvantages of binocular housings
  • Most expensive (most optical components, four image intensifiers, fused eyepieces)
  • Heavier than all other types of housings

Housings

The following panoramic housings have been documented on this wiki:

Binocular Panoramic

Panoramic Binocular Simulation
A simulation of the view through a panoramic binocular. Only the overlapping section between the two circles will be perceived as 3D, while the rest is 2D.

Some binocular housings have the two pods angled outward horizontally by some degrees, either fixed or providing the user with the ability to pan the pods from the traditional binocular configuration.

As a result, the two images that usually overlap to give the user 3D vision shift so only a small portion overlaps, akin to a Venn diagram. This will give the user a wider field of view, usually somewhere around 60-70 degrees instead of the traditional 40 degrees.

Advantages

  • Wider field of vision (requiring less head movement from the user)

Disadvantages

  • Loss of most advantages of binocular systems, like 3D vision and less perceived noise

Housings

The following binocular panoramic housings have been documented on this wiki:

Notes

  1. Using the unaided eye without having to take off the device is advantageous in some situations:
    • Environments with dynamic lighting, where the brighter areas can be observed without restriction
    • Focusing on nearby objects, given enough light, requires no focus adjustment (maps, text, electronic devices, signs, ...)
    • Aiming a weapon is less cumbersome

Further Reading

Study of the Army Research Laboratory:
A Comparison of Monocular, Biocular, and Binocular Night Vision Goggles for Traversing Off-road Terrain on Foot