Light becomes bent and changes direction as it travels from the medium of air to water. Rays of light slow down once they enter the water, causing something like a slower moving traffic jam. This phenomenon is called refraction.

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Due to refraction, fish and other objects within the water look higher, and closer to us, than they actually are. This happens because the light rays diffusing from the fish bend as they leave the water.

Viewing a planet in detail with the naked eye is impossible because it’s so far away that it only takes up a tiny portion of available screen space. If our eyes were larger, then more information could be collected.

Optics is the study oflight

Lenses take advantage of refraction to allow people to see objects more clearly. A convex lens, a lens that curves outwards, like a magnifying glass, causes the light rays to converge to a single point of focus.

One of the best ways to understand the concept of focal length is to capture images of the same subject using different lenses.

what arethe3 typesofoptics?

The example of the ferries wheel illustrates the way that many people think about lenses. You use wide angle lenses to capture a wide view of the world and you use telephoto lenses to capture images of things far away. But you need to shift that thinking to to truly understand lenses and focal length.

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The human eye has a clear, flexible tissue that acts as a lens. Muscles around the eye pull on the lens, flattening it to see things far away. Pushing the tissue together to form a convex lens allows humans to see objects close up.

Diffuse reflection occurs when light hits an object with a rough surface and is bounced back in a scattered way, in all different directions. Most everyday objects present as diffuse reflection because they have tiny imperfections on their surfaces.

The first telescope was invented in the early 1600s. We use these devices to view objects that are extremely far away in detail. Essentially a telescope acts as a larger “eye,” collecting more light than the human eye.

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Camera lenses can use a series of both convex and concave–shaped glass to produce the desired image. The lenses direct light to film or, in the case of a digital camera, to a computer chip that can sense the light.

When light passes into a more dense material (in this case, water), it bends away from the surface between the 2 materials. The light entering the glass of water is called the incident ray, and the light traveling through the water is the refracted ray.

Definitionof opticsin Physics

I have heard photographers say that they don’t need a wide angle lens because they don’t really like landscape photography. And if they need get more into the scene then they can just back up.

Look at the shape of the marker and the size of the buildings in the background. In the 28mm example, I was quite close to the marker while I moved back to capture the image with a 150mm focal length.

Light travels slightly slower through water, as water is more dense than air. Of course, we don’t notice, as it normally travels at almost 186,000 miles per second, but slows down to 143,100 miles per second when it passes through water.

In a vacuum, light travels in a straight line. Starting with Earth’s atmosphere, light that travels to Earth starts to interact with matter. Light behaves and travels differently when going through different material.

A traditional reflector telescope has a concave mirror at one end. The concave mirror collects light that is emitted from the distant stars and other celestial objects and then disperses the light into a wider area.

Galileo Galilei, a 17th century scientist, was fascinated by the behavior of light and invented one of the world's first telescopes. He is also reported to be the first person to try and measure the speed of light.

Concave lenses, lenses that curve inwards, cause light rays to spread out. Like a peephole in a door, they make images look smaller than they are. The center of this type of lens is thinner than its edges.

Optics is the study ofrefraction

Light from the sun that travels through space to reach us on Earth is composed of 7 different colors that all travel at the same speed while in the vacuum. Together these colors combine to form “white light.”

Light reflecting off objects, whether through diffuse or specular reflection, enters our eyes and travels to the retina at the back of our eyes. The retina converts these light rays into electrical signals for the brain to interpret.

We are able to see all sorts of objects around us because light reflects off of them. After a light source hits the surface of an object, it gets reflected in one of 2 ways: specular or diffuse.

Start with your widest angle lens and make sure your subject is in a position where there is something in the background (so not right up against a wall). Get close to the subject so you can almost fill the frame with the foreground subject and capture an image. Then select a longer focal length and back away from your subject so you can fill the frame with the foreground subject and still see the same thing in the background. Compare the images. You can actually do this for multiple focal lengths and not just your widest and longest focal lengths.

Here are some more examples of how focal length affects your image. Be sure to pay attention to the size of the objects in the background.

Light rays appear to bend upon entering water, a phenomenon called refraction. Refraction occurs at the boundary of the 2 media: air and water. This occurs due to the light slowing down slightly as it changes from the air medium to water.

Lenses are specially designed pieces of glass that refract light in different ways. A lens can be used to see incredibly small things using a microscope, or to view things incredibly far away using a telescope.

Specular reflection occurs on smooth surfaces, such as clear, still water, where all the rays of light reflect at the same angle. Each individual ray of light follows the law of reflection: the angle of reflection is equal to the angle of incidence.

Geometric optics describes the behavior of light as it travels in the form of rays. It concentrates particularly on the behavior of light through lenses and media such as water. Rays of light generally travel in a straight line until they hit something.

The human eye has a limited amount of “screen space” available. It can only receive a certain amount of light information that the brain is able to process.

Lenses need to be carefully designed in order to minimize the effect of dispersion. If the lens is designed incorrectly, it may focus different colors of light at different spots, impacting the functionality of the lens.

The light information collected by the concave mirror is reflected onto another mirror, which is reflected into an eyepiece lens. This lens has a  convex shape, magnifying the mirror’s image and taking up lots of eye screen space.

An angle of incidence is the angle that an incident ray makes perpendicular to the surface with which it makes contact. The angle of refraction is the angle made by a refracted ray perpendicular to the refracting surface.

There are two things to notice in this series of images using different focal lengths. 1. The size of the tree and the rubbish bin the background 2. How the shape of the bench changes and becomes more compressed the longer the focal length is used.

Reflector telescopes use mirrors to collect and reflect as much light as possible. The larger the size of the mirror, the more light it can collect. The giant Hubble telescope has a mirror over 8 feet in diameter.

Importanceof optics

So wide angle lenses like the 14-24mm F2.8 have a wide field of view and telephoto lenses like the 70-200mm F2.8 have a narrower field of view.

It is really important for photographers to understand how their different focal lenses see the world because they will be able to choose the lens that fits their vision for the image they have in their mind.

Dispersion occurs because wavelengths of light travel at different rates of speed. This isn’t something that we’re usually able to notice. However, some materials will cause these wavelengths to separate, and that allows us to see rainbows.

A specially designed piece of glass called a prism splits this white light into its 7 wavelengths. Prisms have a triangular cross-section that causes the light to refract when it enters and exits the prism.

While they might be able to back up, the image they capture will be different. You can’t just replicate the look of a wide angle lens by backing up with a longer lens. Just like you can’t replicate the way a long telephoto sees the world by getting closer. It doesn’t work that way.

A 100mm lens on a full frame camera will act like a 150mm lens on a 1.5X cropped sensor camera or like a 160mm lens on a 1.6X cropped sensor camera. So this will affect the field of view of your lens.

Understanding focal lengths is incredibly important in photography. You need to understand how different focal lengths see the world because that will enable you to choose the best focal length for your image.

White light enters the prism as the ray of incidence. Due to the angles within the prism, each of the color wavelengths are refracted at slightly different angles. Red wavelength becomes the least bent, while the violet wavelength is bent the most.

When comparing the two images, the shape of the truck and the compression of the parts of the image are very different. I moved back away from the truck for the 105mm focal length image.

Focal length is a number represented in mm that tells you the angle of view that your lens will capture. The lower the focal length number, the wider the angle of view. For example, a 14mm lens has an angle of view of 114 degrees while a 200mm lens has a focal length of 12 degrees.

It is also important to understand that the size of your sensor affects your focal length. “Full Frame”, “FF” or “FX” sensors are the same size as 35mm film (24mm by 36mm). Cameras with these larger sensors tend to be more expensive that crop sensor cameras with smaller sensors.

Many predators have a natural understanding of the concept of refraction. By using this ability that they were born with, they can compensate their aim when they go hunting for fish and other water–dwelling animals.

With both the human eye and a camera lens, the image is received in an upside–down position. This happens because the light is bent by the curvature of the lens. However, our brains interpret the image the correctly.