Editing Night vision (section)

==Types of ranges==
===Spectral range===
[[File:EM spectrum.svg|thumb|380px|The [[electromagnetic spectrum]], with the [[visible spectrum|visible portion]] highlighted]]

Night-useful spectral range techniques can sense radiation that is invisible to a human observer. Human vision is confined to a small portion of the [[electromagnetic spectrum]] called [[visible spectrum|visible light]]. Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-[[infrared]] or [[ultraviolet]] radiation). Some animals such as the [[mantis shrimp]] and [[trout]] can see using much more of the infrared and/or ultraviolet spectrum than humans.<ref>{{cite journal |last=Milius |first=Susan |year=2012 |title=Mantis shrimp flub color vision test |journal=[[Science News]] |volume=182 |issue=6 |page=11 |jstor=23351000|doi=10.1002/scin.5591820609 }}</ref>

=== Intensity range ===
Sufficient intensity range is simply the ability to see with very small quantities of light.<ref>{{cite web|url=http://math.ucr.edu/home/baez/physics/Quantum/see_a_photon.html|title=The Human Eye and Single Photons}}</ref>

Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These include having a larger eyeball, a larger lens, a larger optical [[aperture]] (the pupils may expand to the physical limit of the eyelids), more rods than cones (or rods exclusively) in the [[retina]], and a [[tapetum lucidum]].

Enhanced intensity range is achieved via technological means through the use of an [[image intensifier]], gain multiplication [[Charge-coupled device|CCD]], or other very low-noise and high-sensitivity arrays of [[photodetector]]s.