Camera structure

The earliest camera structure was very simple, including only a black box, a lens and photosensitive materials. Modern cameras are complex, including lens, aperture, shutter, ranging, framing, photometry, film transmission, counting, self-timer, focusing, zooming and other systems. Modern camera is a complex product integrating optics, precision machinery, electronic technology and chemistry. Let me introduce the structure of the camera to you, hoping to help you!

(a) Structure of the camera: body

Is the fuselage a camera? Mechanical, optical and electrical? The general support of the three major parts. Require fixation, sealing and no deformation. All metal and some engineering plastics.

(2) Camera structure: film winding, counting and film winding mechanism.

These three are usually linked together. When the film is rolled up, the counter of the camera automatically accumulates a number, and the shutter mechanism is tightened accordingly. Automatic film winding device: built-in motor and external motor.

Camera structure: viewfinder

A device used to observe a scene and its range and determine the composition of the picture. It is divided into coaxial and paraxial.

(d) camera structure: focusing device

Focusing is to adjust the distance between the lens and the basement membrane so that the subject can form a clear image on the film or photoreceptor. The focusing device is arranged on the lens. Different types of focus indication.

(5) Camera structure: aperture

Aperture is generally located inside the lens and consists of several pieces of metal, which is used to adjust the aperture size of the lens. The larger the diameter of the aperture, the larger the aperture, and vice versa. The size of the aperture is measured by the coefficient marked on the aperture adjusting ring.

The aperture coefficient is expressed by f, also called f coefficient. The scale of f coefficient is: 1.2 (or1.4) 22.845.6811622. It represents the ratio of focal length to the relative aperture of the lens. The larger the number, the smaller the aperture; The smaller the number, the larger the aperture. The luminous flux difference between the aperture coefficients of every two adjacent stages is twice.

(6) Camera structure: shutter

Shutter is a device used to control the exposure time of camera. With the cooperation of shutter and aperture, you can control the correct exposure required for photography.

(1) shutter speed mark

The common shutter speed signs on cameras are 1, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, etc. These numbers all represent the countdown seconds of the actual shutter speed. For example, 60 means that the exposure time of the shutter is 1/60 seconds, and 125 means that the exposure time is1125 seconds. Shutter speed In addition to digital signs, some cameras also have X, A, B or T shutters, commonly known as X, A, B or T gates.

X-gate indicates the flash synchronization speed of the camera. Single-lens reflex camera with electronic shutter is equipped with a door, sometimes marked with auto, which means that the appropriate exposure time can be automatically determined according to the set aperture size when shooting.

Door b and door t are control devices for long exposure. When using door B, press the shutter button and the shutter will open. Put down the button and the shutter will close. When using the T-door, press the button and the shutter will open. Put down the button, the shutter will not close, and you can only close the shutter by pressing the shutter button again.

2) Type of camera shutter

There are many kinds of camera shutters, which can be divided into mechanical shutter, electronic shutter and program shutter according to the shutter control mode.

Mechanical shutter. The shutter is controlled by a mechanical system. There are two kinds of shutters: mirror shutter and curtain shutter.

Inter-mirror shutter is composed of several metal blades, which are located in the middle of the lens group, so it is also called lens shutter or center shutter.

Curtain shutter is made of special black glue wire or metal curtain, which is installed in front of the photographic film in parallel and close to the focal plane of the camera, so it is also called focal plane shutter.

Electronic shutter. It refers to the automatic control of the opening and closing speed of the shutter through electronic delay circuits and other devices. The electronic shutter uses the built-in battery as the energy source, which can realize the automatic metering and exposure function of the camera. Common electronic shutters mainly include electronic central shutter, electronic curtain shutter and all-electronic shutter. All-electronic shutter adopts linear motor tool to realize real dynamic shutter motion control, or adopts ceramic structure shutter without mechanical transmission, and the photo exposure is completely controlled by electronic control.

Program shutter. Program shutter is a shutter whose aperture size and shutter speed are arranged and combined according to a certain program.

(7) Camera structure: lens

The photographic lens is the optical imaging system of the camera, and the performance and quality of the camera largely depend on the performance and quality of the lens.