How does a telescope work

By Ava Arnold • June 09, 2026

How do you make a homemade telescope? How to make a homemade telescope. Draw a circle on the cardboard around the inner tube. Put a small lens in the center of this circle and make it circular as well. Use a cardboard cutter to cut the inner circle out of the cardboard, then cut out the large circle to remove.

How does the use of telescopes help scientists?

From a practical standpoint, telescopes have helped scientists in many ways. Telescopes, for example, help track meteors and asteroids that could potentially pose a threat to Earth. This is a very practical application because advanced knowledge can help them do something!

What do you use a telescope for?

A telescope is a device used to photograph distant objects. The most popular type of telescope is the optical telescope, which uses a series of lenses or a curved mirror to focus visible light.

What kind of telescope uses only lenses?

refractive telescope. A refracting telescope uses a lens to create an image.
Reflective telescope. A refractive telescope uses a series of mirrors to create an image.
Catadioptric telescope. The catadioptric telescope is also called a Schmidt-Cassegrain telescope or compound telescope.

How do you make your own telescope?

Build a telescope with lenses. Collect materials. Cut the outer tube in half. Cut 2 pieces of the inner tube from the annular tube. Poke a hole in the cap of the ring tube. Drill holes on the outside of the large tube. Glue the eyepiece lens to the removable cap. Cut off the closed end of the outer tube. Place the first spacer in the outer tube.

How large can a telescope be?

Large and small telescopes. For ■■■■■■■ astronomers, a small telescope generally refers to a telescope of 4 inches or less. A medium telescope generally means a telescope between five and eight inches, and a large telescope generally means a little over ten inches.

What is a telescope made out of?

Raw materials. A telescope consists of an optical system (lens and/or mirror) and hardware components that hold the optical system in place and allow you to maneuver and focus. The lenses must be made of optical glass, a special type of glass that is much cleaner and more uniform than normal glass.

What is a telescope mirror?

The main mirror of most modern telescopes consists of a solid glass cylinder, the front surface of which has a polished spherical or parabolic shape. A thin layer of aluminum is applied to the vacuum mirror, which forms the surface of the first mirror with high reflectivity.

How do you make a homemade telescope for kids

DIY telescope 1 Roll a piece of cardboard in a cardboard tube. Add rubber bands. 2 Decorate the telescope with stickers and markers.

How can I get my Telescope to focus?

Slide the two tubes in and out until the subject is in focus. You see the image upside down and enlarged. If you have trouble focusing your telescope, you may need to lengthen the tube by using a larger piece of paper for the end of the eyepiece or a longer cardboard tube (such as a roll of paper).

What's the best way to view an object with a telescope?

Look through the eyepiece and point the other end of the telescope at a distant object. Slide the two tubes in and out until the subject is in focus. You see the image upside down and enlarged.

How do you attach glass to a telescope?

Glue the hot glass to the end of the larger tube. Try to keep the hot glue away from the lens, you want it to be as transparent as possible. Since the pot is remarkably small compared to the width of the tubes, they wanted to use a small cardboard box to hold it to the tube.

How do you make a telescope out of cardboard?

Place the back (smaller) cardboard tube on top of the small cardboard and trace around it. Then place the magnifying glass in the center of the circle you have drawn and trace its outline. Then cut it out and you have a cardboard donut.

How to build your own sharp vision telescope?

You must assemble the following parts of the telescope yourself: 1 main telescope tube 2 main mirror holder * 3 diagonal mirror holder * 4 focus eyepiece * 5 search tubes 6 telescope finder tube holder 7 tripod 8 dust cap of the tube.

What lenses do you need to make a telescope?

Two lenses are required to mount the telescope. They call them objective and ocular lenses. The objective lens should always be convex. Convex lenses are thicker in the center and can be used as magnifying glasses or to focus sunlight. Try to find one that is big and weak.

How do you make a homemade telescope stand

1. Wrap a sheet of paper or cardboard as tightly as possible to create a lens-sized tube with the shortest focal length. This will be the eyepiece. Glue the edges of the eyepiece lens to one end of the tube as carefully as possible.

How big should the Spacers be on a telescope?

Cut 2 pieces of the inner tube from the annular tube. These are your spacers and they should be 1 to 1 inch in diameter. Be sure to use a spiral saw (or other tool) to cut cleanly and straight. Spacers hold the second lens to the outer end of the mail tube.

How do you clean glasses on a telescope?

To clean both sides of the telescopic goggles, simply slide the small tube out of the large tube. Then wipe the glasses with something with a cloth or glasses cloth, or maybe even a fluffy pencil attachment if that works. Then apply the cleaner to something long (such as a much narrower tube).

How do you make a homemade telescope for beginners

To build a telescope, first wrap a 24-inch piece of corrugated cardboard around the diameter of the magnifying glass. Then glue a paper tube and cut 2 slits about 1 inch from each end with scissors. Then insert two different sized magnifying glasses into the slots and glue them together.

How do you make a homemade telescope mount

A book on DIY telescopes is recommended, but here are some tips for making a very simple accessory for the equatorial tube. Plumbing pipes have traditionally been the material from which hobbyist telescope manufacturers build the simplest fixtures.

How do you build a refracting telescope at home?

Glue the lenses to the center of the frame. The lens with the shortest focal length is the eyepiece. Glue this mount lens to the end of the smaller tube. Glue another rimmed lens to the end of the larger tube. 3. Slide the two cardboard tubes together. You have assembled a simple refractive telescope.

How does a gem equatorial telescope mount work?

A threaded rod that lifts the plate passes through a threaded hole in the thick part of the box girder. Essentially, the mount of a GEM telescope consists of two axes mounted at right angles to each other. The shafts themselves are made of hardened steel with a diameter of 30 mm. The shafts are mounted on high quality double row angular contact ball bearings.

What is a telescope and how does a telescope work?

A telescope is a tool astronomers can use to see distant objects. Most telescopes and all large telescopes use curved mirrors to collect and focus the light from the night sky. Early telescopes focused light using curved pieces of clear glass called lenses.

Why are big telescopes needed In astronomy?

In astronomy, as in all other sciences, the quality of the data collected is crucial. To recognize distant and fuzzy objects, special equipment is required. Large telescopes with larger apertures allow you to view these objects and resolve finer details in space.

What do astronomers observe with telescopes ?

Astronomers generally use this primarily to look through telescopes: the moon, planets in your solar system, the sun, objects in deep space, comets, stars, light pollution, novas, supernovas, and satellites.

Why do astronomers use light to study stars?

By studying a star's motion and amount of light, astronomers can determine a star's chemical composition. To calculate massive equations and take into account all elements of physics, chemistry and mathematics, astronomers must also be proficient in computer science.

How do telescopes help scientists help

Why is a Space Telescope better than one on Earth?

Space telescopes like Hubble have a much better understanding of the universe than most of their terrestrial counterparts. They can also detect frequencies and wavelengths across the entire electromagnetic spectrum.

Why is Hubble better than telescopes?

Hubble's orbit outside Earth's distorted atmosphere allows very high-resolution images with significantly lower backlighting than ground-based telescopes. He captured some of the most detailed images with visible light, which allowed him to see deeper into space.

Why are some telescopes placed above Earths atmosphere?

The advantage of space telescopes is that they overcome the blurring effects of the Earth's atmosphere. In addition, many wavelengths in the electromagnetic spectrum do not reach the Earth because they are absorbed or reflected by the Earth's atmosphere.

How do telescopes help scientists make

Telescopes have also discovered new planets and asteroids. These tools helped them make the first reliable measurement of the speed of light. Telescopes have also helped them understand gravity and other fundamental laws of the physical world. Telescopes have also helped them understand the light from the sun and other stars.

How are telescopes used to see the night sky?

Short answer: Early telescopes focused light using curved pieces of clear glass called lenses. However, most contemporary telescopes use curved mirrors to pick up the light from the night sky.

How does the shape of the mirror in a telescope work?

The shape of the mirror or telescope lens focuses the light. You see this light when you look through a telescope. Photo: NASA/JPLCaltech. A telescope is a tool astronomers can use to see distant objects. Most telescopes and all large telescopes use curved mirrors to collect and focus the light from the night sky.

What makes the most powerful telescopes so powerful?

These elements are called optics. The most powerful modern telescopes can see very dark objects immeasurably distant, but their characteristics determine the size of their optics, be they lenses or lenses. For telescopes the size is important, the larger the optics, the more light the telescope can collect, this is called aperture.

What do telescopes allow you to see?

In reality, telescopes are used to view thousands of stars, distant objects, planets and various patterns. The use of telescopes is not only limited to government and meteorological services, but they are also widely used in the daily life of ordinary people and families.

What are some uses of telescopes?

A telescope is an instrument used to observe distant objects. Telescopes are often used to observe planets and stars. Some of the same optical technologies used in telescopes are also used in the manufacture of binoculars and cameras. Important properties of telescopes.

How do telescopes help people?

These tools helped them make the first reliable measurement of the speed of light. Telescopes have also helped them understand gravity and other fundamental laws of the physical world. Telescopes have also helped them understand the light from the sun and other stars.

How do telescopes help scientists find

Either way, you've probably heard of astrology and you may even know your own zodiac sign. From a practical standpoint, telescopes have helped scientists in many ways. Telescopes, for example, help track meteors and asteroids that could potentially pose a threat to Earth.

How are telescopes able to see from space?

From a position above Earth's atmosphere, a telescope could detect light from stars, galaxies and other objects in space before that light is absorbed or distorted. As a result, the view will be much sharper than that of a larger spotting scope.

How are telescopes used as a scientific instrument?

A telescope is used to view objects at a distance, but they often think of telescopes as scientific instruments, looking through them and obtaining images through some optics. For example, the Hubble Space Telescope, although it is a telescope, has no optical parts through which people can see. Instead, the images are captured and broadcast for viewing.

What did the early telescopes show about the universe?

The first telescopes showed that the Earth is not the center of the universe, as previously thought. They also showed mountains and craters on the moon. Later, telescopes showed the geography and climate of the planets in their solar system. Telescopes have also discovered new planets and asteroids.

How do telescopes help scientists grow

Here are some reasons: 1. Telescopes see many colors Telescopes can pick up light that your eyes can't see: radio, microwave, infrared, ultraviolet, X-rays and gamma rays.

How does the size of a telescope affect the light they see?

The larger the mirrors or lenses, the more light the telescope can capture. Then the light combines to form the optic. You see this light when you look through a telescope. The telescope's optics should be close to perfect.

How are radio telescopes different from radio telescopes?

Telescopes collect a lot of light, their pupils are only a few millimeters in diameter, so they can only collect photons in a small area, while telescopes can collect photons in large areas (football fields suitable for children). radio telescopes) 3.

What are the benefits of using telescopes?

List of the advantages of affordable and affordable optical telescopes. Optical telescopes use mirrors or lenses, or both. Easy to use. Optical telescopes are very user-friendly. Visual processing.

What does a scientist use a telescope for?

To study the universe, scientists use different types of telescopes to detect these different types of radiation emitted in the electromagnetic spectrum. Some of these are gamma rays, X-rays, ultraviolet rays, normal visible light (optics), and infrared telescopes.

What are non-optical telescopes used for?

Non-optical telescopes use many of the techniques found in conventional telescopes, but they also use a variety of techniques to convert invisible light into spectacular images. In all cases, a detector is used instead of an eyepiece to capture an image, after which the computer processes the data and creates the final image.

What do you use a telescope for beginners

The TELMU telescope is ideal for beginners. This is a refractive telescope with an aperture of 70 mm and a focal length of 400 mm. The optical glass is covered with it. This coated optical glass improves subject clarity.

What are good telescope for beginners?

There are basically two types of space telescopes for beginners, one is a refracting telescope and the other is a refracting telescope. A reflecting telescope is good for observing distant objects. It eliminates light errors and streaks, but a "drag effect" can occur with these telescopes.

What is the best telescope?

There is no best telescope for everyone. Which one is right for you depends on your lifestyle and astronomical goals. The best telescope is the one you use the most.

How do you use a telescope?

Point the telescope at an astronomical target. Choose a bright object such as a moon or star. Raise or lower the tube and move it back and forth to align the telescope in the general direction of the target. Look through the viewfinder. Adjust the direction of the telescope to center the object in the viewfinder.

What do you use a telescope for photography

The Orion Atlas 10 EQG GoTo is an excellent telescope for experienced observers or astrophotographers, perfect for seeing the finest details or capturing most celestial objects. The GoTo mount can automatically detect and track more than 42,000 objects.

What's the best computerized telescope?

Orion 10135 SkyQuest XT10g. This telescope has been designed with ease of use in mind.
Celestron NexStar 127SLT computer telescope. The design of this telescope is largely inspired by its predecessor, the NexStar 114SLT telescope.
Orion 10134 SkyQuest XT8g. This telescope markets itself through its innovations.
Celestron NexStar 4SE telescope.

What is a DSLR telescope?

A digital single-lens reflex camera is a popular telescopic camera. It uses an automatic mirror system and a penta mirror. This system works by sending the lens light through the viewfinder. The telescope is usually attached to the camera.

What is a digital telescope?

A digital telescope is generally a type of telescope that uses digital functions to give the telescope user more precision and control, or more options for viewing images.

What is the best telescope for personal use?

Best Telescope: Orion 10019 SkyQuest XT1oi Intelliscope
Best Portable Telescope: Celestron 5SE Telescope
Best Auto-Tracking Telescope: Celestron NexStar 130SLT
Best Budget Telescope: Celestron Astromaster 130EQ
Best Telescope for Beginners: Celestron AstroMaster 70AZ

What is the best place to use a telescope?

All factors and trade-offs in the world, there are three main types of locations best suited for telescopes that observe visible light. One is Antarctica, the high peaks of the dry plateaus have little turbulence and are surrounded by darkness.

How to choose the best telescope for You?

How to choose a telescope Pay attention to the size of the telescope opening. The size of the aperture indicates how much light the telescope can absorb from the observed object. Examine the tripod or tripod on which the telescope is mounted. A tripod or tripod should provide a stable base for the telescope. Take a good look at the mounting system.

What do you use a telescope for pictures

The apochromatic refractor uses an extra-low dispersion glass lens because it reduces image sharpness without chromatic aberration. Apo is considered by many to be the best telescope for photography and planetary observation. These telescopes are also compact, lightweight and portable.

How do you take pictures through a telescope?

The cheapest way to take pictures with a telescope is called afocal. This means pointing the telescope at the object you want to photograph and then pointing the camera through the eyepiece to take the picture. This method works well for cameras and cell phones.

Can I take photos through my telescope?

Yes, you can use a telescope to photograph objects in space, but the procedure and equipment settings vary by object. With a portable telescope (such as a desktop Dobsonian) you can use your smartphone to take pictures through the eyepiece of the moon and larger planets such as Jupiter and Saturn.

What do you use a telescope for kids

Using a telescope will help your child develop their imagination and STEM skills and is a great way to introduce them to science and the solar system. There are many options on the market, including toy telescopes to teach young children about stars and planets.

How to choose the best telescope for kids?

Choosing the Right Telescope for Kids 1. Aperture: The opening or diameter of a lens is the amount of light the telescope can receive. A good hole is needed for the telescope.

What is the best telescope for a child?

A good telescope for children that is highly recommended is the Tasco 402x60mm Refracting Telescope. It has high-quality optics for clear and sharp images. The maximum magnification is 402x with a suitable eyepiece.

What is telescope for kids?

Physics for kids. telescopes A telescope is an instrument used to observe distant objects. Telescopes are often used to observe planets and stars. Some of the same optical technology used in telescopes is also used in the manufacture of binoculars and cameras.

What do you use a telescope for hunting

Outdoor telescopes generally offer high-quality optics that give you an excellent view of various ground objects. Moreover, you can use them for different purposes. For example, you can use them to observe different types of animals, closely follow a sports match, etc.

What is the best type of binoculars for hunting?

The Aculon 818x42 is the best zoom hunting binoculars for several reasons. The glasses are made of laminated environmentally friendly glass and have an aspherical shape. These are Porro prism binoculars, which means they have a wide body. Remember that Porro prisms can be better in many ways.

What are the best rifle hunting scopes?

Quick Answer: Top 5 Viewfinders on Nikon Buckmasters II 412 x 40mm Review CVLIFE Bushnell 452104 Elite 4500 Viewfinder 624 x 50 Simmons 8-Point Viewfinder 39 x 50mm Nikon Prostaff Rimfire Ii 412 x 40 Viewfinder.

What is the best magnification for hunting binoculars?

7x to 10x binoculars are ideal for hunting. For long-range shooting, such as B. When hunting pests, it is better to use a magnification of 12 to 16 times. At higher magnifications, you'll need to use a tripod or stabilize the binoculars, as the image is very blurry when you're standing.

What are the top picks for 10x42 binoculars?

5 Best Binoculars 10X42 Vortex Diamondback 10X42 Best Binoculars Overall. The Vortex Optics Diamondback Classic 10x42 binoculars are your favorite binoculars because they offer so many possibilities and few challenges. Upland Perception 10 x 42 Binoculars Ideal for hunting. Celestron 10 x 42 binoculars The best value for money. Bushnell H2O waterproof binoculars.

What do you use a telescope for driving

Driving Telescope Lens is a bio-optical lens system that essentially combines a two-lens optical system with a telescope and connects it to glasses. An additional telescope lens is placed directly above the normal line of sight on the lens.

Can a bioptic telescope be used for driving?

Research confirms that bio-optics can help you drive a car. Their research shows that the vast majority of biopsy guides find the biopsy telescope a useful tool in a variety of guiding tasks. Read the full article.

How do bioptic telescopes help visually impaired people?

Biopsy telescopes can help qualified visually impaired people obtain a driver's license. How does bio-optics help with driving? The problem for visually impaired drivers is that they get so close to a sign or signal that they don't have enough time to configure the correct driving settings.

What should I do with my first telescope?

You've bought your first telescope, an optical time machine that you can use to explore its incredible world. You may be interested in spotting comets, becoming a published astronomical scanner someday, or just want to enjoy the occasional view of the moon and planets.

What kind of Finder do you need for a telescope?

Your telescope most likely has one of two types of telescopes: a red dot scope or a telescopic sight. The telescope is a small telescope that is held on top of the main telescope using the telescope mount. Provides a view of the sky at low magnification, typically 6-10X, and when viewed through an eyepiece].

What do you use a telescope for shooting

In addition to the camera and telescope, you need a few more devices: Diagonal is a mirror or angled prism that provides a perpendicular view. The hanging viewfinder helps you find objects in the sky that you want to photograph. The tube rings and the dovetail rod are adjustable rings for the finder.

How do you use a telescope to take pictures?

First place the eyepiece in the tube, tighten it and place the adapter on the corresponding ring. Then place the ring on the body of the DSLR and connect the whole to the focuser of the telescope. Finally, use the focuser to focus the camera while looking through the viewfinder or the camera's LCD screen.

Is it fun to shoot the Moon with a telescope?

Taking pictures of the moon is fun, easy and very rewarding. Because the moon is so bright and appears so large in the sky that even a small telescope can reveal many interesting surface details.

Do you need a spotting scope for a telescope?

If you want to buy a short-range telescope suitable for ground observation, you need a telescope. Thanks to their compact and lightweight design, the telescopes are less efficient, have variable magnification and are easier to operate.

What are types of telescopes do astronomers use?

Atmospheric Cherenkov telescope for gamma rays opname
Infrared telescope
Radio Telescope
Submillimetre telescope
Ultraviolet telescope (see also ultraviolet astronomy)
X-ray telescope (see also X-ray astronomy) Voltaire telescope

What are the pros and cons of a telescope?

Let's look at the pros and cons. Benefit. Serviceability The refractometer lens does not require the same maintenance as the mirrors of a reflecting telescope and does not require collimation. Refraction telescopes are also generally more durable and are made of ■■■■■■ and less sensitive materials. This tends to prolong its life and is generally the best option if you expect to load a lot in your car, go camping or stargazing.

Which kinds of lenses are in a light microscope?

The two main types of lenses used in optical microscopes today are called objective and ocular lenses (or eyepieces). The eyepiece lens, also called eyepiece lens, is located at the top of the optical tube and the objective lens is located at the bottom.

What is a type of telescope?

There are two main types of telescopes: refractors and reflectors. The part of the telescope that receives light, the lens, determines the type of telescope. A refractive telescope uses a glass lens as its objective.

How does a telescope work for kids

Telescopes for children can help them explore stars and planets and stimulate their imagination and STEM skills. Telescopes use a lens or a curved mirror to collect and focus light from the sky so you can see the stars and planets more clearly.

What are facts about telescope?

A telescope is an instrument that allows you to see the sky better. Interesting Telescope Facts: Galileo is often credited as the inventor of the telescope, although he was simply the first to use it to study the night sky. All early telescopes were refractive.

How does a refracting telescope work?

An astronomical telescope consists of a lens placed in front of the tube. It works to bend light, making parallel rays of light sharp and rays of light that are not parallel to each other converge in the focal plane.

How do space telescopes work?

A telescope is a tool astronomers can use to see distant objects. Most telescopes and all large telescopes use curved mirrors to collect and focus the light from the night sky. Early telescopes focused light using curved pieces of clear glass called lenses.

How does a reflecting telescope work

How does your reflex telescope work? There are mirrors in the tube that collect and reflect the image you see in the sky. Mirrors are curved and reflect light and form an image. There are two reflective surfaces in the telescope that are used to collect the image and reflect it back into the eyepiece.

What is one disadvantage of a reflecting telescope?

Inconvenience of the service. Reflective telescopes are not without problems. Due to its size and open tube design, the mirror needs to be cleaned regularly. Every time it is cleaned, it also has to be leveled, which can be expensive. A shifted telescope produces a blurry or distorted image.

What is the function of a reflecting telescope?

Reflecting telescopes are also called reflectors. Most telescopes that astronomers use today are reflectors. Newtonian telescopes use one mirror to create an image, while another mirror is used to reflect the image from the first mirror.

Is a reflecting telescope better than a refracting telescope?

Reflective telescopes are most useful in astronomy because they provide clear vision at long distances, while refractive telescopes are designed for everyday applications, such as use in camera lens systems. To be fair, the reflex and refractive telescopes are handy and useful.

What is a reflecting telescope used for?

The most important milestone of telescopes: reflection telescopes Reflectors are not only used to study the visible part of the electromagnetic spectrum, but also to study shorter and longer neighboring regions (ultraviolet and infrared).

What is a telescope lens?

The telescopic lens, which can be used in photography and cinematography, is an accessory that can magnify distant objects.

When was the telescope invented

Galileo was the first to use a telescope for astronomical purposes in 1609 (400 years ago in 2009, now celebrated as the International Year of Astronomy).

Who was the first person to use a telescope?

However, Galileo was the first person to use the telescope for astronomical purposes after hearing of Lippershi's work in 1609.

What are facts about the telescope?

What you need to know about telescopes The James Webb Space Telescope succeeded the Hubble telescope. The first telescopes were used by maritime and military merchants. Most observatories are built in the mountains, where the air is shallower and cleaner. Today, many astronomers work remotely from the telescope itself.

What was Galileo's first telescope?

Galileo's first telescope was a tube with two lenses. His first attempt was a triple instrument, followed by another that magnified objects about nine times. He showed the latest device to the Venetian Senate, hoping to impress them with its commercial and military potential.

How does a telescope work in space

The space telescope works in the same way as Newton's reflecting telescope. There are only 2 differences: the telescope is in space and sends the recorded image to Earth via radio signals. Structural difference between space telescopes and ground-based telescopes There are two mirrors in the Newtonian ground-based telescope.

How do telescopes help them study space?

Modern telescopes like NASA's Hubble Space Telescope provide evidence for billions of galaxies, each of which, like the Sun, contains billions of stars. Some new telescopes allow them to explore objects in the universe by detecting heat, radio waves or the X-rays they emit. Telescopes are now revealing planets around other stars.

What are space telescopes used for?

A space telescope is a space instrument used to observe distant planets, galaxies, and other space objects. Many space telescopes have been placed in orbit and have greatly improved their understanding of the universe.

How does a telescope and a microscope work?

In a telescope, the real object is far away and the intermediate image is smaller than the object itself. In the microscope, the real object is very close and the intermediate image is larger than the object itself. With a telescope and microscope, the eyepiece magnifies the intermediate image in the telescope, but this is the only magnification.

How are space-based telescopes useful?

A space telescope is a scientific instrument that observes astronomical objects and conducts other investigations outside the Earth's atmosphere. Unlike ground-based telescopes, space telescopes provide more accurate observations because they are free from atmospheric turbulence and radiation distortion.

How does a modern telescope work?

How do modern telescopes work? Telescopes capture light in two ways. Reflective telescopes focus the light using a series of mirrors, while refractive telescopes use lenses. For research purposes, reflecting telescopes have become the norm due to their relatively simple design and they work with large mirrors.

How do different types of telescopes work?

There are two main types of telescopes: refractors and reflectors. The part of the telescope that receives light, called the lens, determines the type of telescope. A refractive telescope uses a glass lens as its objective. The glass lens is on the front of the telescope and light bends (refractors) as it passes through the lens.

how does a telescope work