How To Choose and Buy A Telescope
A telescope makes a wonderful gift for someone who has an interest in the night sky. Even a majority of the smallest inexpensive telescopes are capable of revealing the rings of Saturn, the cloud belts of Jupiter, hundreds of star clusters and even distant galaxies. With a medium or large telescope, amateur astronomers rarely see everything there is to see with a telescope, even after years of. 10 best telescopes money can buy| Interesting Engineering.
It can feel like you need to learn a whole new language just to understand your options. Amateur astronomy is a rewarding shopp that you and your family can enjoy for years to come. Shp ready to explore the Universe!
Believe it or not, magnification or "power" is one of the shpp important factors to consider when you're choosing a telescope. The single greatest misconception about telescopes is that you need to have lots of magnification to see objects.
Not true. Instead, the telescope's light-gathering ability, also called apertureplays the biggest role in determining how much detail you see in objects. Some manufacturers of "toy store" telescopes take advantage of this common misconception. Be skeptical of outrageous claims of x or x magnification on inexpensive telescopes. It's true that magnification levels can be pushed sky high with certain go and optical appliances.
However, image quality suffers severely to the point where it can be difficult to make out any detail at all. It's far better to view with a telescope of larger aperture and moderate magnification than to push a smaller scope to ultra-high magnification levels. If you choose a larger aperture scope with lower magnification, the object will appear a bit smaller in the eyepiece.
But because the image you see will be of far better quality, you'll actually see a how to fix air suspension more detail!
The most important attribute of a telescope is its aperture size. This is the diameter of the telescope's light-gathering lens or mirror.
It's usually measured in millimeters or inches. Why is aperture size shopp Because it's like having a bigger eye with which to view the what color walls go with beige carpet. The human eye is a marvel of genetics, but it suop a relatively poor job of seeing in the dark.
Humans have a flr pupil diameter of only about 7mm at full dilation. All the light our retina can receive is what's able to squeeze telescops how to shop for a telescope that tiny opening. No wonder we're only able to discern the brightest of deep-space objects! In effect, we see the heavens with built-in telescopes only about one-quarter inch in diameter. Man-made fr provide a remedy. The telescope's optics then focus this light into a beam small enough to get through our pupil.
We're able q see much dimmer objects. Z why aperture is so important. OK, so a telescope's ability to gather light is tepescope. Should you, then, look for the largest telescope you can possibly afford?
Maybe, but not necessarily. You also need to consider portability and ease of use. Before you consider specific telescope options, ask how to shop for a telescope where you will want to use your new telescope. If the answer is in the backyard, then a great big telescope might be perfect. But if you want to take how to shop for a telescope telescope to dark-sky locations for better viewing away from city lights, size and weight become important factors.
If you plan on taking your scope on camping trips, it will be sharing space in your car with other gear. If you want to be able to take a quick peek at the night sky, choose a simple telescope that sets up in just a few minutes. Move on to Part 2: Choosing an Optical Design. Space Fo as a Tourist Industry.
Astronomy and Telescopes: Frequently Asked Questions. Welcome to Telescopes Have questions about an item or need advice on selecting the right astronomy gear?
Our team of telescope experts is here to help! Avid amateur astronomers themselves, they've tested products in the field and can provide personalized recommendations. Drop us an email at info telescopesplus. We'll get back to you as soon as possible, usually within what is so bad about obama healthcare plan business day.
A Word about Magnification Believe it or not, magnification or "power" is one of the least important factors to consider when you're choosing a telescope. Aperture: Bigger is Better The most important dor of a telescope is its aperture size. Beyond Aperture OK, so a telescope's ability to gather light is paramount.
Welcome to Telescopes August 11, Backyard astronomy is a fun and rewarding hobby that can Thank you for subscribing! Ask The Experts Have questions about an item or need advice on selecting the right astronomy gear?
What telescope should you buy?
Shop for the best telescope for your stargazing needs at High Point Scientific. Buying telescopes online is easy with High Point Scientific, thanks to our extensive selection of quality products from brands like Celestron, Meade, Orion and more. Buy telescopes online at High Point Scientific today!/5(K). Jul 28, · Shop Telescopes By Type. Best Telescopes for Kids. Orion StarBlast Astro Reflector Telescope Kit. $ Shop Now. Beginner Telescopes. Orion SpaceProbe II 76mm Equatorial Reflector Telescope Kit. $ Shop Now. Beginner Telescopes. Orion GoScope III 70mm Refractor Travel Telescope Kit. Jan 25, · So if you see a mm department-store telescope scope labeled as delivering " power!!!", you'll know it's advertising hype, and you’d be wise to keep shopping. This field near the center of the Virgo Galaxy Cluster is spectacular when viewed at low magnification through a large-aperture telescope under pristine dark skies.
Choosing Your Astronomy Equipment. By: Adrian R. Ashford January 25, 0. You can unsubscribe anytime. This is an exciting time to become an amateur astronomer. Never before have novice stargazers been presented with such a vast array of telescopes and accessories to pursue their hobby. Naturally, this brings the burden of choice: the bewildering variety makes it hard for an uninformed consumer to make the right decision on what type of telescope to buy.
Whether you're seriously considering buying your first telescope or just daydreaming about it, this guide will help you narrow your options. We'll start by exploring the basic features common to all telescopes, and then look at some specific designs. We'll also look at the tradeoffs, because every instrument has its advantages and disadvantages.
Before you buy anything, you must determine what's important to you. What do you most want to look at? How dark is your sky? How experienced an observer are you? How much are you prepared to spend? Where will you store your telescope, and how much weight are you willing to carry? Answer these key questions, familiarize yourself with what's on the market, and you'll be well on your way to choosing a telescope that will satisfy you for many years to come.
This guide concentrates on visual observing, as opposed to astrophotography. Before examining the different telescopes available, it's worth knowing the basics of how they work.
The most important aspect of any telescope is its aperture , the diameter of its main optical component, which can be either a lens or a mirror.
A scope's aperture determines both its light-gathering ability how bright the image appears and its resolving power how sharp the image appears. Apertures commonly recommended for beginner telescopes range anywhere from 2. Does that mean you should rush out and buy the biggest telescope that you can afford? Not necessarily. Telescopes with big lenses or mirrors tend to be heavy and bulky. That may not be a problem if you keep your scope stored in a shed and wheel it out for use, but a bulky telescope could be a show-stopper if you need to carry it up and down many flights of stairs, want to take it on an airplane, or store it in a cramped apartment.
Although it may be less capable, even the smallest telescope is a huge improvement over your unaided eyes, which have a measly 7 mm 0. That means that a little mm scope gathers times as much light as your eyes, revealing amazing detail on the Moon and pleasing views of all the planets, as well as showing hundreds of star clusters, nebulae, and galaxies.
When seeing a telescope for the first time, a novice often asks, "How much does it magnify? But don't get the idea that super-high powers will do you much good. Two main factors limit how much power you can use productively with a given instrument: aperture again and atmospheric conditions. Only so much detail exists in the image created by a telescope's main mirror or lens, so you must find the optimum range of magnifications to see this detail — without spreading out the target's precious light too much, making a dim object too dim to see, or turning a bright object into a big blur.
How much power is too much? And that's if the scope has perfect optics and the night air happens to be unusually steady. So if you see a mm department-store telescope scope labeled as delivering " power!!! Now you know the range of useful magnifications for any given instrument. But how do you get them? What do those little numbers on the eyepieces tell you about the magnification they give?
Every scope has a focal length , which is effectively the distance from the main lens or mirror to the image it forms. This is not always the same as the length of the tube, since, as we'll see later, some telescopes "fold" the light path internally.
Focal length is the large number you'll often see printed or engraved on the front or back of the scope, usually between about and 3, millimeters. Eyepieces have focal lengths too — 25mm or 10mm, for example. To find the magnification any combination of telescope and eyepiece yields, simply divide the focal length of the scope by that of the eyepiece. Our telescope calculator tool offers an easy way to make these calculations.
For visual observing, the focal ratio determines your choice of eyepieces. Unfortunately, no commercially available eyepiece has a focal length anywhere near 95 mm.
Budget-priced telescopes usually accept only the smaller size, but most premium-quality scopes accept both sizes. That allows them to use long-focal-length eyepieces that provide low magnifications and wide fields of view. Even with the best telescope, you'll notice that you can discern finer lunar or planetary detail on some nights than on others.
Often the sharpness of the view even changes from one second to the next. At high power, you'll see that planets and stars shimmer and blur on most nights. The fault lies not with the scope but with Earth's turbulent atmosphere, and sometimes with very local conditions such as warm air rising from a nearby asphalt driveway that soaked up solar heat all day.
Astronomers refer to turbulent nights as having bad "seeing. Large apertures allow observers to pick out faint objects and fine detail on the Moon and planets, but regardless of aperture, the better the seeing, the better the view. Everyone is thrilled by their first view of Saturn and its amazing rings, even when the sky conditions are mediocre. There are three main culprits: unrealistic expectations again , light pollution, and inexperience. Any way you slice it, galaxies are faint.
Our own Milky Way is a perfect example. Few sights in nature are as beautiful as its soft glow arching across the sky on a clear moonless night far from city lights. It is the stuff of legends, a sight familiar to all humanity before the electric light was invented. Telescopes cannot fix that. They make celestial objects appear bigger, but they cannot make their light more intense. Fortunately for urban and suburban astronomers, many deep-sky objects are bright enough to shine through heavy light pollution, though you may need more aperture to see them than you would from a dark location.
These urban-friendly deep-sky objects include star clusters, double stars, and small planetary nebulae. As for galaxies, urbanites still can see their bright centers; in fact even small binoculars can show the core of the Andromeda Galaxy from the middle of a major city.
Its light has traveled across intergalactic space for 2. Having gained an appreciation of a few important principles governing a telescope's performance, we can now explore the different types available. You'll be forgiven for thinking there's an infinite variety from the ads in the astronomical press. Yet for all their varied shapes and sizes, telescopes can be divided into three classes: refractors , reflectors , and catadioptrics.
A refractor is the stereotype of how a telescope is supposed to look — a long, gleaming tube with a large lens in front and the eyepiece at the back. When properly designed and built, refractors generally deliver sharper and brighter images per inch of aperture than any other design. In general, a top-quality 4-inch refractor shows deep-sky objects about as well as a 5-inch reflector or catadioptric, and might even do a bit better on the planets.
Most telescopes with apertures of 80 mm or less are refractors. Therefore, refractors dominate both the bottom end of the market, where people can only afford very small apertures and also the market for highly portable high-performance telescopes. Small refractors also perform to full capacity almost as soon as you bring them outside, whereas large reflectors and catadioptrics deliver mediocre high-power images until their mirrors reach the temperature of the outside air, which can take an hour or more.
For these reasons small refractors are well suited to those seeking a "grab and go" instrument or who have no desire to tinker with the optics. Unfortunately, refractors do not scale up well, for several reasons. The cost of building a good lens rises very steeply as the aperture increases — much more so than for mirrors. By contrast, a 6-inch reflector is considered rather small for a beginner, and many advanced observers own reflectors with mirrors 12 to 30 inches in diameter.
False color can be a serious problem for people who want to view the Moon and planetsat high power, but it can be minimized by using either long focal ratios or special glasses. For achromats , whose lenses are made with traditional flint and crown glass, false color is essentially invisible when the focal ratio is at least three times the aperture in inches. Long tubes are especially problematic for refractors because the eyepiece is at the bottom of the telescope. That means that the pivot point needs to be above your head, and that in turn requires a tall, heavy, expensive tripod.
These so-called short-tube achromats sacrifice a certain degree of high-power performance in favor of portability and a wide field of view. Fortunately, modern technology makes it possible to combine the benefits of short-tube and long-tube refractors — at a price. Apochromats , or APO s, use lenses made with extra-low dispersion ED glasses and other materials to reduce false color dramatically.
Not only does this alleviate the problem of overlong tubes, it also allows these scopes to deliver gorgeous wide-field views at low magnifications as well as flawless high-power images. APOs are also particularly good for wide-field astrophotography. Apochromats used to be extremely expensive, but prices have come down significantly in recent years. The cheaper but still excellent! An ED refractor is now a plausible choice for a beginner who wants a rugged, portable, highly versatile telescope and is willing to accept the limited image brightness and resolution that are inevitable consequences of small aperture.
The second type of telescope, the reflector , uses a mirror to gather and focus light. Its most common form is the Newtonian reflector invented by Isaac Newton , with a specially curved concave dish-shaped primary mirror at the bottom end of the telescope.
Near the top, a small, flat, diagonal secondary mirror directs the light from the primary to the side of the tube, where it's met by a conveniently placed eyepiece. If you want the most aperture for your money, the reflector is the scope for you.
When well made and maintained, a reflector can provide sharp, contrasty images of all manner of celestial objects at a small fraction of the cost of an equal-aperture refractor. Newtonians have two additional important advantages. And the eyepiece is at the top of the tube, meaning that the pivot point is well below your head. That allows them to be used with low tripods or, in the case of the popular Dobsonian design, with no tripod at all.