5 Best Telescopes for Deep Space (Galaxies, Star Clusters & Nebulae)

I guess most of the amateur astronomers are all about imaging and observing those deep sky objects – DSO, usually called ‘nebulae.’

In the beginning, you’ll find online some nice images taken from the best Earth and space telescopes. You’ll probably have no idea what those objects are, where they can be found, nor is it possible to observe them live through a telescope. Most of the people think that deep sky objects (DSO) are unimaginably far, far away and impossible to look at them from Earth. That couldn’t be further from the truth, especially the latter one.

Deep space objects are thousands of light-years away, some galaxies are millions of light-years away, but their size is enormous. Therefore their angular size in the sky is quite large as seen from Earth. There are several hundreds of deep-sky objects whose angular size is larger than the largest planets, Jupiter and Saturn. There are dozen DSO that is larger than the Moon as seen from Earth.

So why can’t you see them? They are very faint. You’ll need a large ‘photon bucket’ in order to capture those celestial gems. Those photon buckets are called telescopes, in order to help you to channel more photons to your retina. There are a handful of DSOs that are visible with the naked eye, that’s why any optical instrument can help, from the smallest binoculars to the largest custom made, one of a kind Dobsonians – the real deep-sky telescope. 

We Recommend

Best value/price ratio

Orion
SkyQuest XX12i

Best budget option

Sky-Watcher
8″ Dobsonian

Best for the money

Orion
SkyQuest XX16g GoTo

What you need for deep space observing

Deep-sky objects or sometimes called deep space objects can be viewed quite easily. Most people tend to buy the largest telescopes in order to have a better view of those faint DSOs. While that is mostly true, you can start with any kind of binoculars, and even the smallest one can help, you just need to know the position where to look for them. 

No matter what kind of instrument you are using for hunting DSOs, knowing the position is always the key, and sometimes you’ll have to know what to look for, knowing the appearance of the object you are looking for can be crucial, like brightness, size, and form, because it can happen that your object is in your field of view, but you can’t recognize or even notice it. For that, you’ll need experience.

Unlike observing planets where you need the largest magnification possible, here, in deep sky observing, you need the largest aperture possible in order to have a better contrast of those faint objects.

Also, a very important element in deep space observing is using narrowband filters. Maybe these are the most important accessories in your ‘deep-sky arsenal.’ With narrowband filters, you’ll get much better contrast, more details, and when changing different filters (wavelengths), you’ll notice different features and characteristics. I would recommend using UHC, O-III, and H-beta filters.

Another important factor while observing deep-sky objects is the quality of the sky, light-polluted areas near large cities are something you should avoid. In most cases, you should go more than 5 miles away from the city lights in order to have a moderate quality sky. In situations like this, narrowband filters are almost a must in order to filter out unwanted light pollution.

What’s the best type of telescope for observing deep space objects?

A Dobsonian reflector telescope is probably the only contender out there. This type of reflecting (Newtonian) telescope is the best of its kind for visual observing the DSO. Its design, easy to use, portability and lightweight large objective mirrors make it very popular among amateur astronomers.

If you are considering refracting telescopes, you can use them, but they are a bit more expensive at larger apertures and not so portable. Big refractors are not intended for visual observing of deep-sky objects. If you already own one, you can always use it, with some wisely chosen eyepieces even the cheapest refractor can give you some enjoyable view of the night sky.

You can also use catadioptric telescopes, but those are very expensive with bulky design in general and heavy mounts. Although someone not familiar with ‘star-hopping’ could have use of its GoTo mount for locating DSO, you can have a Dobsonian with GoTo base. But then again, where’s the fun without star hopping?

A quick tip: Almost every DSOs are observed black and white, there is no hue. Don’t expect to see any color like the images from astrophotography. That’s because we are using only night sight photoreceptor cells.

Dobsonian telescopes are synonymous with visual observing deep sky objects. With a nice set of eyepieces and proper narrowband filters, that will be everything. You’ll ever need for 99% of the nebulae. What about the remaining 1%? For that, you’ll need some additional $40 for a basic pair of binoculars.

On the other side of the spectrum, you have the binoculars, yes even the smaller ones like 8X40 (8 X magnification, 40 mm aperture) can be used to enjoy the night sky at the largest galaxies, star clusters, and nebulae. I would always recommend using a tripod for stargazing when you have greater magnification than 8. 

In my opinion, 10X50 and 11X70 are the most suitable for astronomy. You can also opt for the more expensive, high-performance astronomy binoculars like 25X100, but for those, a more advanced tripod is a must. For astronomy, sometimes the ultra-wide field of view is spectacular; that’s why I would also recommend 4X30 for nice stellar nightscapes of the Milky Way.

Aperture is the key

Oh, yes! The larger, the better.

Telescopes are light-gathering buckets that are channeling the photons to your retina. If you double the aperture size, you are quadrupling the light-gathering power… more light means you’ll see fainter details, and the object will have a higher contrast.

In my experience, telescopes with 6” aperture are a great place to start, 12” are my favorite where you have the best ratio of price/performance/portability, there are some really compact and portable telescopes. Apertures between 12” and 16” is the sweet spot for the best price/performance ratio, from 12” to 16” you are doubling the light-gathering power and doubling the price, so you can choose whether you’ll lean towards budget or towards performance. 

Dobson refracting telescopes with apertures 18” and larger are more than just a commodity, that’s where you are paying a premium for every percent of increment. You must know that with doubling the size, you won’t get even two limiting magnitudes.

So the difference from 12” to 16” telescope, the limiting magnitude will jump just from 14.8 to 15.5, but the price will be double. That’s why I use my 12” scope 8 out of 10 times while going stargazing, it’s powerful enough not to notice a lot of difference to 16,” but it’s very compact for easy transport.

Don’t forget the filters

Often overlooked for visual astronomy, narrowband fIlters are possibly the best astronomy accessories that you will have. Those little glasses are small and somewhat expensive, especially the 2” versions, but I’m sure you’ll find a good use for them. Narrowband filters are a must if you want to minimize the light pollution or you want to see different details on some of the nebulae.

There are three kinds of narrowband filters most used for visual observation and possibly the only ones: UHC, O-III and H-beta.

  • UHC (Ultra High Contrast) filter is suitable for almost every DSO except for stars, double stars and some of the open star clusters. This filter cuts out the light pollution and some of the atmosphere glow, so you’ll get a better contrasted view. You can use it for any object that has nebulosity like galaxies, diffuse nebulae, as well as star clusters, but in star clusters, you are cutting away some of the starlight as well.
  • O III filter is probably the highest contrast filter you can use. It filters out everything but the certain wavelength of doubly ionized oxygen (green hues) where most of the emission nebulae are brightest, like planetary nebulae, supernova remnants and stellar nurseries (H II regions). This filter is not for galaxies, stars nor any kind of star clusters.
  • H-beta filter is not that spectacular like the O III filter, mostly because there is not much radiation at that wavelength compared to H-alpha, that’s why this filter can be used for the brightest objects only. This filter is good only for stellar nurseries (H II regions) where hydrogen is strongly ionized.

There is one more filter called CLS, this one is not that popular now because it’s not filtering enough of the light pollution. This one was very useful against light pollution from those orange street lights (sodium lamps) that are rarely used today. That’s why nowadays CLS is almost obsolete.

How to choose the right deep space telescope?

Well, that’s easy. Just buy the largest aperture Dobson telescope for your budget, and you are set.

That’s funny but also a really honest and helpful answer, now let’s elaborate when you should choose one characteristic over another.

  • Aperture – in visual observing, this is the most important thing you should focus on wider aperture, more light, more contrast, more details.
  • Focal length – the higher focal length you have, the better clarity and higher angular separation will be.
  • Field of view – this will be determined with the eyepieces. Their apparent field of view and focal length will give you the true field of view of the scope.
  • Mount – Dobsonian telescopes use rocker bases that are a very cheap but very practical design. Some rocker boxes can be better and a lot smoother than others because of their design and materials used.
  • Portability and weight – this is probably the most important factor that doesn’t affect the viewing quality but can affect your willingness to go out and use it.

First of all, telescopes for visual observing the night sky are a lot cheaper. Their optics are not so refined like on the telescopes for astrophotography and all the other parts are either missing or are a lot cheaper. They don’t have the complex, steady, and motorized mounts. You don’t need guiding scopes or other anti-dew electronics. You don’t need expensive imaging and capturing devices. Telescopes for astrophotography can be used for visual observing, but their prices will be much higher with specs that are much worse.

Because better scopes can get really big, really fast, that’s why you should be aware of the portability, sometimes you might pay a premium for more compact design telescope over bulky scope with the same characteristics.

Smaller scopes are great for the largest and brightest DSO. You might ask why? Because you can achieve a very wide field of view with the shorter focal length for the largest deep sky objects, like the Andromeda galaxy, the Orion nebula, the Pleiades, Double Cluster in Perseus, etc.

Best telescopes for deep space

1. Orion 8944 SkyQuest XT6 Classic Dobsonian Telescope

This Dobsonian has an unbeatable price; you can justify buying it with only using it once a year. Definitely the best beginner Dobsonian telescope you can find. 

Nice 6″ (150 mm) aperture at an amazing price that makes all the rest sub 6” telescopes obsolete. 

With this one, you can enjoy the deep space nebulae with adequate clarity in good detail. 

With this 6” you can observe the entire Messier catalog objects, a good chunk of NGC and IC catalog, and of course, the Moon, Moon’s craters, and the planets. 

You can keep on using this scope even after you buy a mammoth 16”+ so you can have the largest DSO from end to end in your field of view.

Check the price of Orion 8944 SkyQuest XT6 Classic Dobsonian Telescope here

What we liked

  • Great value
  • Great for beginners
  • Easy to assemble
  • Excellent focal length
  • Very good for viewing the Moon
  • Great for planets

What we didn’t like

  • No fine focusing
  • Very bulky tube and mount
  • 20 mm Plossl eyepiece
  • Sliding could be smoother
  • Very low eyepiece position for lower altitude objects

Type: Dobsonian reflecting telescope
Aperture: 6”
Focal length: 1200 mm
Focal ratio: f/8
Limiting stellar magnitude: 13.5
Weight: 34.4 lbs. (15.8 kg)
What’s special about it: Amazing price, great for beginners.

2. Sky-Watcher 8" Collapsible Dobsonian Telescope

Eight inches of aperture makes this a mid-range scope for the beginners and more serious astronomers. 

The collapsible tube makes it more compact and helps with portability, but the rocker mount, though very steady, is still bulky to transport. 

Dobsonians are always easy to use, easy to collimate, easy for maintenance, most of them are affordable, and you get great value for money.

There are two eyepieces in the box 10 mm and 25 mm Plössl, but those are just mediocre to low grade. I would recommend you to immediately buy the cheap aspherical eyepieces or something better in order to unlock the great potential that this telescope possesses. 

Although the manufacturer quotes that the maximum magnification is at 400x, with this scope, you can enjoy the highest useful magnifications at around 120x with mid-range eyepieces and push the limit to 150x with high-end eyepieces if you are buying this telescope for deep space objects than it’s the light-gathering power which matters more than magnification. 

Although I prefer red dot scopes, this one comes with a very nice right-angled 8X50 viewfinder. You can easily replace it or attach a red dot next to the viewfinder. Because of its larger aperture, for observing the Moon, you’ll need an ND-8 filter, or maybe a variable ND filter could be an even better choice.

Check the price of Sky-Watcher 8″ Collapsible Dobsonian Telescope here

What we liked

  • Wide aperture
  • Collapsible tube
  • Nice viewfinder
  • Nice long focal length
  • Great price for 8-inch scope
  • Easy to use
  • Teflon rocker mount bearings 

What we didn’t like

  • No fine focusing
  • Bulky rocker base
  • Eyepieces are low quality

Type: Collapsible Dobsonian reflecting telescope
Aperture: 8”
Focal length: 1200 mm
Focal ratio: f/6
Limiting stellar magnitude: 14.2
Weight: 53 lbs. (24 kg)
What’s special about it: Great for beginners, semi-compact, quite powerful.

3. Sky-Watcher 12" Collapsible Dobsonian Telescope

The 12” version is virtually the same quality as the 8” version, but with a larger aperture, longer focal length, a far better fine-tune focuser, and not much more weight to it, which is good for portability. 

If you are a backyard astronomer and you don’t plan to travel to dark locations, then this semi-compact design can be great. Just don’t forget to use your UHC filter when stargazing in your backyard.

Same as 8” version, I would strongly recommend you to immediately buy at least the cheap aspherical eyepieces because the included Plossls are garbage for this kind of a telescope. 

Its larger aperture and longer focal length can utilize the best eyepieces out there. In order to experience the full potential of this 12-inch scope, maybe you should buy at least one high-end eyepiece with an ultra-wide apparent field of view at 100°.

Check the price of Sky-Watcher 12″ Collapsible Dobsonian Telescope here

What we liked

  • Very good aperture size
  • DSO hunter
  • High contrast for DSO
  • Nice, large focal length
  • Collapsible tube
  • Well fine-tune focuser
  • Great overall performance
  • Nice viewfinder
  • Easy to collimate

What we didn’t like

  • Very bulky rocker base
  • Both eyepieces are low quality

Type: Collapsible Dobsonian reflecting telescope
Aperture: 12”
Focal length: 1500 mm
Focal ratio: f/5
Limiting stellar magnitude: 14.9
Weight: 58 lbs. (27 kg)
What’s special about it: Great for advanced users, semi-compact, very powerful telescope.

4. Orion 10023 SkyQuest XX12i IntelliScope Truss Dobsonian Telescope

Sometimes you may like the Push-To telescope. This one is probably the most compact and affordable Push-To telescope out there. 

Although Dobsonian GoTo and Push-To are not my cup of tea, somebody else might enjoy this kind of setup. 

In order to use the Push-To system, you need to set up the IntelliScope system with a vertical position and 2-star alignment. 

After that, the system is all set up and the hand controller will guide you to the location of the desired object. 

If you want to view the planets, you’ll need to enter the correct date and time as well. This is a much more compact version of a Dobsonian reflecting telescope than the previously mentioned Sky-Watcher scopes. 

First of all, the tube disassembles into three segments, one where the primary mirror is, one segment with the secondary mirror, and truss poles as the third part. The rocker base (mount) disassembles into smaller parts as well without needing any tools.

Even with this scope, there are two eyepieces in the box. The first one is a 10 mm Plossl, which is complete rubbish and the 35 mm, 2” Plossl is somewhat useful for larger DSO, but you won’t get much of a contrast with it. 

That’s why I would recommend buying at least the cheap aspherical eyepieces for a start, and later you should definitely buy one high-end eyepiece between 10 mm and 15 mm with an ultra-wide apparent field of view at around 100°.

Check the price of Orion 10023 SkyQuest XX12i IntelliScope Truss Dobsonian Telescope here

What we liked

  • Nice and smooth alt-azimuth movement (panning and tilting)
  • Very large 12” aperture
  • Free Starry Night software
  • Real DSO hunter
  • High contrast for DSO
  • Large focal length
  • Very compact scope and base
  • Very portable
  • 14,000 DSO database
  • Fine-tune dual-speed (11:1) Crayford focuser
  • Amazing overall performance
  • 9×50 finderscope
  • Cooling fan

What we didn’t like

  • Price
  • Longer time for full assembly
  • Eyepieces with low-quality optics
  • Need batteries for the hand controller

Type: IntelliScope (Push-To) Truss Dobsonian Telescope
Aperture: 12”
Focal length: 1500 mm
Focal ratio: f/5
Limiting stellar magnitude: 15.1
Weight: 83 lbs. (38 kg)
What’s special about it: Very compact when disassembled, great portability, very powerful telescope, great for DSO hunting.

5. Orion 8968 SkyQuest XX16g GoTo Truss Tube Dobsonian Telescope

A colossal piece of hardware, a really large aperture, and great focal length are sometimes too big. You should be prepared to lift heavy weights or always have a helping hand next to you for transport and assembly. 

The secondary mirror is very heavy and very bulky to transport. If you are doing it alone, full unpacking and assembly could take up to 20 min. 

When pointed at zenith, the eyepiece is at 72 in. (182 cm) from the ground, that means some of you’ll need small steps in order to get to the eyepiece. 

The full GoTo motorized base makes this scope very unique in features and capabilities. In the beginning, you should set up the system by aligning with 2 stars and enter the current date and time. 

After alignment, you can use it as a GoTo system or regular Dobsonian by moving it manually. Luckily for this scope, there is a ‘closed-loop’ system that detects the manual movement of the scope, so you never lose alignment. There are very useful tension adjustments for nice and smooth manual panning and lifting.

Check the price of Orion 8968 SkyQuest XX16g GoTo Truss Tube Dobsonian Telescope here

What we liked

  • Mammoth 16” mirror
  • 4x more light than 8” telescope
  • Amazing for DSO and planets
  • 8 trusses for rigidness
  • Full GoTo functionality
  • Closed-loop system for manual use
  • 42,000 object in the database
  • Base breaks in 4 sections for better transport
  • Alt-az tension adjustments
  • Very compact scope and base
  • Designed for maximum portability 

What we didn’t like

  • 2x more expensive than regular 16” Dobsonian
  • 15-20 min. to full unpacking and assembly
  • Cloth shroud not included
  • 12V battery not included

Type: GoTo Truss Tube Dobsonian Telescope
Aperture: 16”
Focal length: 1800 mm
Focal ratio: f/4.4
Limiting stellar magnitude: 15.7
Weight: 174.0 lbs. (79 kg)
What’s special about it: Very compact when disassembled, great portability for that telescope size, extremely powerful telescope, made for DSO observing.

 

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