.bv

.bv is the Internet country code top-level domain (ccTLD) reserved for the uninhabited Norwegian dependent territory of Bouvet Island. The domain name registry and sponsor is Norid, but .bv is not open for registration. .bv was designated on 21 August 1997 and was placed under the .no registry Norid. Norwegian policy states that .no is sufficient for those institutions connected to Bouvet Island, and therefore the domain is not open to registration. It is Norwegian policy not to commercialize domain resources, so there are no plans to sell .bv. Should the domain later come into use, it will be under the regulation of the Norwegian Post and Telecommunications Authority and follow the same policy as .no.

History

Bouvet Island is an uninhabited volcanic island in the South Atlantic Ocean. It was claimed by Norway in 1927. The domain was allocated on 21 August 1997, at the same time .sj was allocated for Svalbard and Jan Mayen. The allocation occurred because the Internet Assigned Numbers Authority (IANA) assigns ccTLDs to all entities with an ISO 3166 code, for which Bouvet Island is designated BV.

BV

BV, B.V., Bv, bV, or bv may refer to:

APEX system

APEX stands for Additive system of Photographic EXposure, which was proposed in the 1960 ASA standard for monochrome film speed, ASA PH2.5-1960, as a means of simplifying exposure computation.

Exposure equation

Until the late 1960s, cameras did not have built-in exposure meters, and many photographers did not have external exposure meters. Consequently, it often was necessary to calculate exposure from lighting conditions. The relationship of recommended photographic exposure to a scene's average luminance is given by the camera exposure equation

where

is the relative aperture (f-number)

is the exposure time ("shutter speed") in seconds

is the average scene luminance ("brightness")

is the ASA arithmetic film speed

is the reflected-light meter calibration constant

Use of the symbol for luminance reflects photographic industry practice at the time of ASA PH2.5-1960; current SI practice prefers the symbol . German sources typically used for the relative aperture. Many authors now use and for relative aperture and exposure time.