on video How does a camera work?

Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there's no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight — it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it's reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn’t until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hits the material, which through the course of photography's history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects — but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn't meet at the right point, the image will look blurry or out-of-focus. A lens's focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that’s able to bring far objects close.

Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there's no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight — it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it's reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn’t until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hits the material, which through the course of photography's history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects — but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn't meet at the right point, the image will look blurry or out-of-focus. A lens's focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that’s able to bring far objects close.

Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there's no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight — it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it's reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn’t until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hits the material, which through the course of photography's history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects — but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn't meet at the right point, the image will look blurry or out-of-focus. A lens's focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that’s able to bring far objects close.

Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there's no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight — it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it's reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn’t until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hits the material, which through the course of photography's history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects — but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn't meet at the right point, the image will look blurry or out-of-focus. A lens's focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that’s able to bring far objects close.