Slr camera how does it work

This allows you to look at the subject through a mirror through your lens. With mirrorless cameras, this system is missing so you can view your subjects via a digital image in the viewfinder or on the screen. By looking directly through the lens while shooting, you view the subjects in an analogous way while capturing them. Another feature of the SLR camera is the interchangeable lens.

After Full Frame, this is about the largest sensor you can get. This makes clear and sharp images with great detail. To fit an APS C sensor and a mirror system into a camera, a large body is needed. Although smaller models exist today, the size of most bodies is a disadvantage of the SLR camera. An SLR camera often has various manual and semi automatic settings. On the camera, you'll find various buttons and wheels with which you can adjust the settings during shooting.

For example, you can manually set the best lighting for the perfect image. Or choose a special mode that allows you to take a good portrait photo. The more expensive the model, the more options there are on the device. In basic cases the viewfinder is just a rectangular-shaped hole and in more complex cases the viewfinder is somehow connected to the main lens for focusing purposes twin-lens reflex TLR cameras for example , but still these systems are simpler than SLR cameras.

So, how does a SLR camera work or what makes it so complex? The key parts for the light to move through the camera are: lens, mirror, focusing screen, prism and eye piece. Probably you already know that the lens is made of several optical elements and it is for focusing the light on the film. The mirror is small and light, capable of moving up and down. Sometimes the focusing screen also has some features that will help you focus the picture, but these are not important at the moment.

The rays of light all start at the same point -- the candle's flame -- and then are constantly diverging. A converging lens takes those rays and redirects them so they are all converging back to one point.

At the point where the rays converge, you get a real image of the candle. In the next couple of sections, we'll look at some of the variables that determine how this real image is formed. We've seen that a real image is formed by light moving through a convex lens. The nature of this real image varies depending on how the light travels through the lens. This light path depends on two major factors:. The angle of light entry changes when you move the object closer or farther away from the lens.

You can see this in the diagram below. The light beams from the pencil point enter the lens at a sharper angle when the pencil is closer to the lens and a more obtuse angle when the pencil is farther away. Consequently, light beams that enter at a sharper angle will exit at a more obtuse angle, and vice versa.

The total "bending angle" at any particular point on the lens remains constant. As you can see, light beams from a closer point converge farther away from the lens than light beams from a point that's farther away. In other words, the real image of a closer object forms farther away from the lens than the real image from a more distant object.

You can observe this phenomenon with a simple experiment. Light a candle in the dark, and hold a magnifying glass between it and the wall. You will see an upside down image of the candle on the wall. If the real image of the candle does not fall directly on the wall, it will appear somewhat blurry.

The light beams from a particular point don't quite converge at this point. To focus the image, move the magnifying glass closer or farther away from the candle.

This is what you're doing when you turn the lens of a camera to focus it -- you're moving it closer or farther away from the film surface. As you move the lens, you can line up the focused real image of an object so it falls directly on the film surface. You now know that at any one point, a lens bends light beams to a certain total degree, no matter the light beam's angle of entry. This total "bending angle" is determined by the structure of the lens.

In the last section, we saw that at any one point, a lens bends light beams to a certain total degree, no matter the light beam's angle of entry. A lens with a rounder shape a center that extends out farther will have a more acute bending angle. Basically, curving the lens out increases the distance between different points on the lens. This increases the amount of time that one part of the light wave is moving faster than another part, so the light makes a sharper turn.

Increasing the bending angle has an obvious effect. Light beams from a particular point will converge at a point closer to the lens.

In a lens with a flatter shape, light beams will not turn as sharply. Consequently, the light beams will converge farther away from the lens. To put it another way, the focused real image forms farther away from the lens when the lens has a flatter surface.

Increasing the distance between the lens and the real image actually increases the total size of the real image. If you think about it, this makes perfect sense. Think of a projector: As you move the projector farther away from the screen, the image becomes larger. To put it simply, the light beams keep spreading apart as they travel toward the screen. The same basic thing happens in a camera. As the distance between the lens and the real image increases, the light beams spread out more, forming a larger real image.

But the size of the film stays constant. When you attach a very flat lens, it projects a large real image but the film is only exposed to the middle part of it. Basically, the lens zeroes in on the middle of the frame, magnifying a small section of the scene in front of you.

A rounder lens produces a smaller real image, so the film surface sees a much wider area of the scene at reduced magnification. Professional cameras let you attach different lenses so you can see the scene at various magnifications. The magnification power of a lens is described by its focal length. In cameras, the focal length is defined as the distance between the lens and the real image of an object in the far distance the moon for example.

A higher focal length number indicates a greater image magnification. Different lenses are suited to different situations. If you're taking a picture of a mountain range, you might want to use a telephoto lens , a lens with an especially long focal length.

This lens lets you zero in on specific elements in the distance, so you can create tighter compositions. If you're taking a close-up portrait, you might use a wide-angle lens. This lens has a much shorter focal length, so it shrinks the scene in front of you. The entire face is exposed to the film even if the subject is only a foot away from the camera. A standard 50 mm camera lens doesn't significantly magnify or shrink the image, making it ideal for shooting objects that aren't especially close or far away.

A camera lens is actually several lenses combined into one unit. A single converging lens could form a real image on the film, but it would be warped by a number of aberrations.

One of the most significant warping factors is that different colors of light bend differently when moving through a lens. This chromatic aberration essentially produces an image where the colors are not lined up correctly. Cameras compensate for this using several lenses made of different materials. The lenses each handle colors differently, and when you combine them in a certain way, the colors are realigned.

In a zoom lens , you can move different lens elements back and forth. By changing the distance between particular lenses, you can adjust the magnification power -- the focal length -- of the lens as a whole. The chemical component in a traditional camera is film.

Essentially, when you expose film to a real image , it makes a chemical record of the pattern of light. It does this with a collection of tiny light-sensitive grains, spread out in a chemical suspension on a strip of plastic.

There are also some disadvantages of this system: SLR cameras tend to be bulkier and heavier than viewfinder cameras. SLR cameras tend to be noisier than other types because of the physical mechanism. This isn't usually an issue but it can be a problem if you are trying to shoot discreetly e. SLR cameras are relatively complex so there is more chance of them breaking down.