LVS

LVS may refer to one of the following:

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.

LVS-86

LVS-86 is a model of tramcar developed at the Leningrad Tram Manufacturing Plant in the former Soviet Union. LVS stands for "Leningrad-made articulated tram" in Russian, and 86 refers to the model year. The design was based on the LVS-80 tramcar. 473 LVS-86s were built from 1987 until 1997. LVS-86s currently run in Saint Petersburg and formerly in Arkhangelsk. Tram operation in Arkhangelsk ceased in July 2004.

Technical specifications

LVS-86 is a 1,524-millimetre (5 ft) Russian gauge tramcar with six axles. Two equal-sized sections articulate around a central mm bogie. Each section has two electric motors which can also act as brakes, supplemented by pneumatic brakes and magnetic track brakes. The central bogie is not motorized. The motors are controlled by potentiometers or thyristors.

The tram has 27 seats and holds 327 riders when fully loaded. Most trams have four-segment folding doors at the front and rear and at the middle of each section. LVS-86 is 22.5 metres long, 2.55 metres wide, and 3.15 m high. Unloaded, it weighs 29.5 tonnes. Multiple trams can be linked together and controlled from a single cab.