What is the function of the aperture on the camera?

1, you can adjust the amount of light entering the lens.

When taking pictures, if the light is strong, you should narrow the aperture, if the light is dark, you should open the aperture. That is to say, the smaller the F value (other parameters remain unchanged), the more favorable it is for shooting at night. The adjusting ring on the rotating lens or the knob on the digital camera body is used to adjust the aperture size.

2. Aperture is the most important factor to determine the depth of field.

Small aperture (large aperture value), deep view, large aperture (small aperture value), deep view! For example, nearsighted friends, if they don't wear glasses, always habitually squint at things, so they can often see things clearly. To use photographic terminology, this is called: narrowing the aperture (pupil) and increasing the depth of field!

Extended data:

Aperture type:

1, fixed

The simplest camera only has a fixed aperture with a circular hole-waterhouse aperture.

2. Variable

Only a series of circular holes with different sizes are arranged around a disk with a central axis; Rotating the disc can move the circular hole with appropriate size to the optical axis, thus controlling the aperture. John Vaught Hauser invented this kind of aperture in the middle of19th century.

3, cat's eye type

The cat's eye aperture consists of a metal plate with an oval or diamond hole in the middle, which is divided into two parts. Two metal sheets with semi-elliptical or semi-diamond holes are arranged in opposite rows and moved relative to each other to form a cat's eye aperture. Cat's eye aperture is mostly used for simple cameras.

4. Iris type

It consists of a plurality of overlapping arc-shaped thin metal blades, and the size of the central circular hole can be changed by the clutch of the blades. Some cameras can change the aperture of the diaphragm by rotating the ring on the lens barrel, while others automatically change the aperture of the diaphragm by controlling the micro-motor through the microprocessor chip.

5. Instantaneous

The aperture of a SLR camera is instantaneous, and only when the shutter is opened will the aperture be reduced to a predetermined size. Usually the aperture is at the maximum position.

6. Shutter

The aperture of some simple cameras has shutter function. Most of these double shutter apertures are cat's eye apertures with two blades. Unlike the simple cat's eye aperture, the double shutter aperture is completely closed at ordinary times. At the moment when the shutter is pressed, the double shutter aperture is opened to a predetermined aperture, and then closed immediately after keeping the aperture for a predetermined shutter opening time. In this way, the aperture has the function of double shutter.

7. Hole

We already know that the speed of a lens refers to its ability to transmit light. If we don't want the lens to receive the maximum amount of light, we need a way to reduce the amount of light in the lens. We achieve this goal by changing the aperture size of the lens. Aperture is a circular hole produced by the variable aperture (blade group) in the center of the lens. ?

References:

Baidu Encyclopedia-Aperture (photographic terminology)