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There are several possible names which all mean roughly the same thing, including the term "lens opening" used in the question itself. Others include:
* Aperture * Diaphragm * Stop (because it "stops" the passage of light) * f/stop * (obsolete) Waterhouse Stop The largest lens opening at which a lens may be set is called its lens speed.For example, a 50 mm lens with a maximum aperture of f/2.8 is referred to as an f/2.8 lens.
Probably most commonly the lens opening is called the aperture, and apertures are typically rated or measured in f/stops. In most modern cameras the aperture is adjustable, using a metal leaf diaphragm called the "iris diaphragm" (since it operates just like the iris in your eye) which can be opened or closed to let in more or less light.
The adjustable iris diaphragm together with the adjustable shutter speed work together to control the total amount of light admitted to the camera during exposure. The diaphragm and shutter may be user controlled, camera controlled, both, or fixed, depending on the camera. It is not known who invented the first iris diaphragm, but a certain J. H. Brown of the Royal Microscopical Society seems to have invented an "improved" iris diaphragm around 1867.
The term "f/stop" refers to FACTORIAL stop. The physical area of the opening is expressed as a factor or ratio of the focal length, calculated by dividing the focal length by the diameter of the opening.
Waterhouse stops are now obsolete, but before someone invented the metal leaf continuously adjustable iris diaphragm, some early camera lenses came with a set of metal plates with holes in varying sizes which could be inserted into a slot in the lens to control the amount of light admitted. The invention was credited to John Waterhouse of Halifax in 1858.
Wiki User
∙ 15y ago
Wiki User
∙ 15y agoThis is called the "iris".
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What part of the plant gives off water vapor through openings called stomata?
Plant leaves have openings called stomata.
Has two openings called nares?
The nose.
What are the Opening of the nose?
The nostrils / nares are the openings in the nose.
What are openings in the body lined with?
Natural ones are called orifices. Artificial ones are called stomas.
What are openings in the cell membrane called?
Protein channels
What is the upper lens called?
The upper lens is called the ocular lens or the eyepiece.
What is upper lens called?
The upper lens is called the ocular lens or the eyepiece.
What are small openings on the underside of a leaf called?
They are called stomata, openings or pores in the epidermis of leaves.
Why is concave lens called a negative lens?
Concave lens is called a negative lens because it has a negative focal length.
Why a convex lens is called converging lens?
when a beam of light is passed through the convex lens it converges the beam of ligth.hence convex lens is called a converging lens.
Why a convex lens is called a converging lens?
when a beam of light is passed through the convex lens it converges the beam of ligth.hence convex lens is called a converging lens.
Why is a convex lens called a converging lens?
when a beam of light is passed through the convex lens it converges the beam of ligth.hence convex lens is called a converging lens.
Why is convex lens called a converging lens?
when a beam of light is passed through the convex lens it converges the beam of ligth.hence convex lens is called a converging lens.
Why a convex lens called converging lens?
when a beam of light is passed through the convex lens it converges the beam of ligth.hence convex lens is called a converging lens.
A lens that curves outward is called?
)( is a concave lens() is a convex lens
What is the upper lens?
The upper lens is called the ocular lens or the eyepiece.
Lens in eye?
It is called the optic lens
