How Camera Works - It's Anatomy
I’m sure you use your camera every day, but do you know how it works? This article will break down the basics of a camera’s anatomy and what each piece does.
The first step to understanding how a camera works is looking at the parts that make up the machine’s body.
A lens captures light and focuses it on film or an image sensor (or light-sensitive electronic device) that produces a photograph. Most cameras use transparent plastic film as their storage medium; it comes in spools like those used with ordinary household tape recorders.
You can find the film in a variety of forms with different degrees of light sensitivity. The shutter controls the intensity of light reaching the film or electronic sensor. The lens is a mighty magnifying glass, with some cameras using several lenses in a single assembly.
Image sensors react to incoming light according to how much electricity each tiny area of film or sensor receives. Most cameras feature a viewfinder that allows you to look through the lens and frame your shot before taking it.
Camera lenses are sophisticated combinations of many different types of glass, usually including elements made from other minerals such as calcium and barium fluorite.
The lens gathers light and focuses it through a series of lenses to the film or sensor. Just like humans, cameras have “farsightedness” problems; objects that are very close (such as a finger in front of your nose) may not be in focus. This is the job of the “focus ring” (usually at the end of the lens; some lenses have a separate dial for this).
The aperture regulates how much light passes through the lens and reaches the film or sensor. It works like a pupil: when it is vast, more light is allowed through, and when it is small, less light passes.
Small apertures (or f-stops) such as f/22 mean that the aperture hole inside the lens is tiny. Larger apertures (like f/2.8) indicate that the aperture hole inside the camera lens is relatively large, allowing more light to pass through.
The aperture is set with the “aperture ring” (usually found at the end of the lens). Depending on how much you are willing to spend, camera lenses can have variable-sized apertures to control overexposure.
The shutter is a small metal “curtain” in front of the aperture. It works as a Venetian blind, with a tab at the bottom that opens and closes to allow more or less light into the aperture.
Depending on how much you are willing to spend, camera lenses can have variable-sized apertures to control overexposure.
When you take a photo with many cameras, the aperture opens, and the shutter closes in one-fifth of a second or so (shutter speeds are measured in fractions of a second; they may be shown as “1/500,” for example).
Exposure is when light reaches the film or sensor. The more time the shutter is open, the more light reaches the film.
The size of your aperture determines how bright or dark your photo will be. The aperture opens and closes much faster than the shutter–1/2000th of a second or faster in many cameras, although some have shutters in digital camerasHigheropen for a full second
The film speed, indicated in ASA or ISO numbers, determines how sensitive the film is to light. Higher speeds mean that the film needs less exposure to record an image; a tripod would not be needed when using high-speed film under normal circumstances.
With most cameras, you focus by turning a ring on the lens. The distance your subject must be from the camera to take a focused picture is called the “focal length.” Zoom lenses can change focal length, allowing you to move farther or closer to your subject
Importance Of Understanding Light
Understanding light is essential for taking quality photographs. If you have too little light, you will not take a good picture because the film or sensor won’t pick up enough detail in your subject. If there’s too much light, however, your photo can look washed out and overexposed.
The aperture regulates how much light passes through the lens and reaches the film or sensor. The shutter speed controls how long light can pass through the aperture to get the film or sensor.
Lighting equipment for a camera includes a flash, a tripod, filters, and other accessories which allow you to control how much light reaches the film or sensor.
The concept of “ambient” light is that of the natural lighting of a scene. For example, you might be photographing someone at noon on a sunny day. The dominant light source, in this case, would be sunlight — which would provide “ambient” light for your photo.
The concept of “artificial” lighting is an additional source of light used to illuminate your subject.
For example, if you were photographing someone in a dark room lit only by the light of a lamp on a table, your artificial lighting would be the light from that lamp — which would create light for your photo (in this case, the light wouldn’t come from sunlight).
ISO, Megapixels, And Sensors
Higher ISO, larger megapixels, and larger sensors all mean higher quality.
The film or sensor is made of millions of tiny “photosites” that can detect light. The more photosites on a camera’s film or sensor, the more sensitive it is to light. And, with high sensitivity comes low noise.
In digital cameras, higher ISO means higher sensitivity, resulting in more “noise” (graininess). There is a point of diminishing returns, however. Larger pixels on a camera’s sensor are better at capturing light; the result is better quality photos with less noise.
To understand megapixels, put simply: they allow you to enlarge your photo. The more megapixels your camera has, the larger you can make your print.
SLR stands for “Single-Lens Reflex.” SLRs have a mirror that allows you to look through the viewfinder. When you take a picture, the mirror flips up, out of the way, allowing light to hit the film or sensor.
SLR cameras are usually divided into two categories: “full-frame” and “crop.” Full frame means that your camera’s film or sensor is the same size as a frame of 35mm film (36 x 24 mm). Most digital SLRs (and all professional DSLRs) are full-frame.
SLR cameras usually allow interchangeable lenses.
Digital Compact Cameras: Digital compact cameras are small, usually lightweight models with fixed lenses. Some can take high-quality images; others offer less image quality.
Compact cameras are often called “point-and-shoots” because they don’t offer manual shutter speed, aperture, and ISO controls. They usually have a fairly wide-angle lens, allowing you to include more in the picture.
The most common situation in which a DSLR is preferable to a compact camera is when you need more control over the depth of field.
DSLRs offer “full-time” manual focus, whereas compact cameras usually only allow manual focusing at one specific distance. Another common reason for using a DSLR is taking pictures in very low light with no tripod.
DSLRs often have a larger image sensor, allowing more light to be captured. And because of the size of the sensor, the image produced by a DSLR is sometimes called “full-frame” (even if it uses an APS-C sized sensor).
Bridge Cameras: Bridge cameras are in between compacts and DSLRs — they offer many of the features of a DSLR with the convenience of a deal.
Bridge cameras usually have larger image sensors than compacts but are not quite as large as DSLRs. They often have some manual controls and more zoom power than compact cameras. Many bridge cameras also offer some degree of waterproofing, although this can vary widely depending on the model and manufacturer.
Mirrorless Cameras: Mirrorless cameras are digital cameras that do not use a mirror or SLR system. Instead, the image is shown on the back screen for as long as you hold down the shutter button. As a result, they are generally smaller and lighter than SLRs.
Mirrorless cameras offer the best of compacts and DSLRs: They have interchangeable lenses but are about the same size as compact cameras.
Many mirrorless cameras allow you to preview the depth of field directly in the viewfinder, which is advantageous for photographers who want to control their “bokeh.”
Using the automatic settings on your camera is fine for everyday snapshots, but to get professional-looking results, you’ll need to familiarize yourself with some of the manual controls.
Yes, many things go into the perfect picture. However, understanding your camera is one of the cornerstones for finding great images.
Q: Is it possible to determine how many megapixels you need without consulting an expert?
A: Yes. Generally speaking, the more pixels your camera sensor has, the more you can enlarge your photo without sacrificing clarity. A 4-megapixel photo will print only up to 5 x 7 inches at good quality. You’ll need 8 or 9 megapixels on an excellent enlargement. At that size, even 10 megapixels may not produce perfect results.
Q: I understand how the aperture affects depth of field, but how does shutter speed affect the picture?
A: Shutter speed determines how long the camera’s shutter is open when taking a photo. This can affect the exposure since it’s possible to extend the exposure time to let in more light. But shutter speed also affects another aspect of your picture: motion.
If you take a photo with a slow shutter speed, you’ll capture any moving objects as streaks instead of clear images. If you use a fast shutter speed when shooting something moving, the thing effect will appear to be frozen in time.
Q: Is it better to buy a camera with more pixels or one that has a larger sensor?
A: It depends on what you want to do with your images. A large image sensor can create higher-quality pictures and give you more control over the depth of field (how much is in focus) than a camera with fewer pixels. However, if you just want standard-size prints of your images, you can use the same number of pixels on any size sensor.
Q: What are some common mistakes that beginners make?
A: There are many mistakes that new photographers tend to make. The most common one forgets to use the LCD screen on the back of the camera. Many cameras have an LCD screen that shows you exactly what you’re getting when you take a picture instead of what you see through the lens. It’s essential to look at this screen before taking a photo — just like professional photographers do!