f-stop
The iris of the camera allows more or less light to enter the camera.
In photography, the iris refers to the part of the camera lens that controls the amount of light entering the camera, while the aperture refers to the opening in the lens that allows light to pass through. The iris adjusts the size of the aperture to regulate the exposure of the image.
The diaphragm, often called the "iris" diaphragm for its identical form and function to the iris in your eye, regulates the physical amount of light allowed to pass through a camera lens. It may be called the "iris," the "diaphragm," the "iris diaphragm," the "stop," or the "aperture." All mean the same thing.Physically, the diaphragm or iris diaphragm is made up of overlapping thin opaque metal plates, usually six or eight, which can be adjusted to increase or decrease the diameter of the hole, called the stop, in the center of the lens. The diaphragm is often located at the optical center of the lens between sets of elements. On manual cameras there is usually a ring around the lens barrel marked in f/stops for adjustment of the diaphragm.The iris (diaphragm) in your eye, working properly, automatically opens or closes in response to light level. When you are exposed to strong light the iris closes down (or "stops" down) to a smaller diameter, decreasing the light reaching your retina (equivalent to the film or sensor in your camera). In dim light, the iris opens up to admit more light. The diaphragm in your camera works the same way, and on modern cameras it's often equally automatic. You may never even notice it's working.In a camera, the iris diaphragm and the shutter have to work together to control the total exposure. The iris diaphragm controls the amount of light, and the shutter controls the amount of light over time. Depending on the make and model of the camera, shutter and diaphragm may be manual, automatic or both. The diaphragm is the mechanism that varies the size of the aperture; the opening that allows light into the camera.
The shutter acts like the iris of the eye because it lets the proper amount of light.
iris
The iris diaphragm is named after the iris, the colored part of the eye, because of its similar appearance and function. Just like the iris controls the amount of light entering the eye, the iris diaphragm in a camera lens controls the amount of light entering the camera.
iris
An autoiris is a camera iris which adjusts automatically based on light levels.
Cameras have an iris diaphragm.
The iris has an opening, called the pupil, through which light enters the eye.
A camera's diaphragm and your eye's iris perform the same function in the same way. They both control how much light is allowed through the lens by expanding and contracting.
The same as the irises of your eyes, it controls the amount of light that passes through the aperture.