Naked eye

A naked eye is a figure of speech, referring to human visual perception unaided by enhancing equipment such as a telescope or binoculars. Often used in astronomy when referring to events that can be viewed by the general public, for example astronomical conjunctions, comets or meteor showers.

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Basic sky lore and various tests show an impressive wealth of phenomena that can be seen with the unaided eye.

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The basic accuracies of human eyes are:

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• Angular resolution 1–2′ (about 0,02?), which corresponds to 30–60 cm at a 1 km distance
• Field of view (FOV): simultaneous visual perception in an area of about 130 × 160?
• Faint stars up to +6,5^m magnitude
• Photometry (brightness) to ?10 percent or 1% of intensity — in a range between night and day of 1 : 10 000 000 000 !
• Symmetries of 10–20″ (5–10 cm per 1 km) — see the excellent measurements of Tycho Brahe and the old Egyptians
• Interval estimations (e. g. at a plan on paper) to 3–5 per cent.
• Unconscious recognizing of movement ==> "alarm system" & reflexes
• Speed estimation to 5–10 percent.

Every day with this "instrument" we estimate a lot of things and their dimensions, without being conscious of this:

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• the distances and 3-dimensional position of things and persons,
• the speed of the cars at the street we are driving
• the vertical (plumb line) and the slope of plain things
• luminosities and colours — and its changes by time and direction
• ... and other qualities of objects.

Figure of speech: A figure of speech, sometimes termed a rhetorical figure or device, or elocution, is a word or phrase that departs from straightforward, literal language. Figures of speech are often used and crafted for emphasis, freshness of expression, or clarity. However, clarity may also suffer from their use....

Visual perception: Visual perception is one of the senses, consisting of the ability to detect light and interpret (see) it as the perception known as sight or naked eye vision. Vision has a specific sensory system, the visual system....

Telescope: A telescope (from the Greek tele = 'far' and skopein = 'to look or see'; teleskopos = 'far-seeing') is an astronomical tool which gathers and focuses electromagnetic radiation. Telescopes increase the apparent angular size of ingerso objects, as well as their apparent brightness....

Naked eye related Images and Photos (experimental)

Naked Spur, The (DVD)	Naked Chef (Paperback)	Naked Lunch	Naked World (DVD)
Eye Plug	Naked Viburnum	Eye Chart	Eye Mosaic
Naked Gun 33 1/3	Lennon Naked (DVD)	Eye Sea IV	The Eye