Quick Answer: What Is The Best Focal Length For Telescope?

How do you know if a telescope is good?

As a rule of thumb, your telescope should have at least 2.8 inches (70 mm) aperture — and preferably more.

Dobsonian telescopes, which are reflectors with a simple mount, provide lots of aperture at relatively low cost.

A larger aperture lets you see fainter objects and finer detail than a smaller one can..

How do you increase the focal length of a telescope?

You can do that by inserting a Barlow lens in front of the eyepiece. A Barlow lens is a diverging lens, that is to say, this type of lens causes light rays to spread out. When used in a telescope, a Barlow lens increases the telescope’s focal length, thus, magnifying the image.

What can you see with a 102mm telescope?

Although they won’t be able to see them in the greatest of detail, you can easily see things like the rings of Saturn, as well as most nebulae. Although they’re easily visible, especially at 130mm equivalents, seeing nebulae are very dependent on the light pollution in your area.

What can you see with a 40mm telescope?

Orion nebula and Andromeda galaxy will be easy objects for 40mm scope. Again one can see many stars in Pleiades and many other star clusters. There are also many brilliant double stars within the range of this instrument. The problem with many small telescopes is that they don’t come with proper mount (stand!)

What is a good focal ratio for a telescope?

For such objects, a focal ratio of f/10 or more is ideal. But if you want to see wide views of star clusters, galaxies, and the Milky Way, a lower focal ratio is better. You get less magnification, but you see more of the sky. Wide field telescopes have a focal ratio of f/7 or less.

Is Focal Length important in telescopes?

The importance of focal length is in determining magnification. The longer the focal length, the greater the magnification with a given eyepiece. … For example, a telescope with a 1000mm focal length gives a magnification of 40x with a 25mm eyepiece.

What type of telescope is best for viewing planets?

Five of the Best Telescopes to See PlanetsCelestron 21037 PowerSeeker 70EQ.Orion AstroView 90mm Refractor.Celestron NexStar 4 SE Maksutov-Cassegrain.Sky-Watcher ProED 100mm Doublet APO Refractor (tube only)Meade LX200 8″ Schmidt-Cassegrain.

What magnification do you need to see Jupiter?

Generally a magnification of 30-50x the aperture of your telescope (in inches) works well on nights of average seeing. So if you have a 4-inch telescope, try 120x to 200x. If you have razor sharp optics and steady sky, you can get away with even more magnification.

Which telescope lens is stronger?

Magnification is determined simply by dividing the focal length of the telescope by the focal length of the eyepiece. This means that a smaller number on an eyepiece gives a higher magnification. A 10mm eyepiece would provide twice as much magnification as a 20mm eyepiece.

How big of a telescope do you need to see galaxies?

If you want to observe galaxies — and I mean really get something out of the time you put in at the eyepiece — you have to use a telescope with an aperture of 8 inches or more. Bode’s Galaxy (M81) glows brightly enough to show up through binoculars, but the larger the telescope you can point at it, the better.

What magnification do I need to see the rings of Saturn?

The rings of Saturn should be visible in even the smallest telescope at 25x [magnified by 25 times]. A good 3-inch scope at 50x [magnified by 50 times] can show them as a separate structure detached on all sides from the ball of the planet.

Which telescope is best for deep space viewing?

The Orion AstroView 120ST Equatorial Refractor Telescope provides great wide-field high contrast images for the intermediate observer or astrophotographer. It is perfect for viewing or photographing the moon, planets and even deep-sky objects.

What magnification do you need to see Venus?

The best way is with a telescope. Even a small telescope, say 60 mm in aperture, can show you Venus and allow you to see it go through its phases. I would recommend using a magnification of 50X or higher while observing venus using a telescope.

Which is the best telescope to view galaxies?

The 10 Best Telescopes Comparison ChartProduct NameRankingOrion 09007 SpaceProbe 130ST Equatorial Reflector Telescope3 4.30Celestron – NexStar 8SE Telescope4 4.10Celestron – NexStar 6SE Telescope5 4.10Meade Instruments 209006 Infinity 102mm AZ Refractor Telescope6 3.806 more rows

What does focal length mean on a telescope?

Generally expressed, focal length is the distance (given in millimeters) between the telescope’s primary lens or mirror and the point where the light rays come together in focus.

Which power of a telescope is the most important?

Magnification is the least important power of a telescope. Amateur and professional astronomers know that the light-gathering power and resolving power are the most important. These two abilities depend critically on the objective, so they make sure the optics of the objective are excellent.

How can I make my telescope more powerful?

To increase the magnification on a telescope, astronomers use eyepieces, which are usually sold along with a telescope. The eyepiece is the lens that is placed at the end of a telescope’s tube, which is where the entering light converges, also called the focal plane of the telescope.

What do refracting telescopes use to focus?

Refracting telescopes use lenses to focus the light, and reflecting telescopes use mirrors. … Refracting telescopes work by using two lenses to focus the light and make it look like the object is closer to you than it really is. Both lenses are in a shape that’s called ‘convex’.

How powerful does a telescope have to be to see the rings of Saturn?

The rings of Saturn should be visible in even the smallest telescope at 25x [magnified by 25 times]. A good 3-inch scope at 50x [magnified by 50 times] can show them as a separate structure detached on all sides from the ball of the planet.

Is a 70mm telescope good?

However, a 70 mm refractor (which collects 36% more light than a 60mm telescope) is considered by many amateur astronomers to be the minimum size for a good quality beginner refractor telescope. It is acceptable for observing bright objects like lunar details, planets, star clusters, and bright double stars.