Maksutov and Newtonian telescopes are popular among night sky enthusiasts. Both types are suitable for beginners and they both have their pros and cons.
Here we discuss how they differ, in what way they are similar, and in what these scopes excel at.
What Is A Maksutov Telescope?
Maksutov telescopes (Maks) are catadioptric telescopes, meaning they use a design that combines mirror and lenses.
In a Maksutov telescope light enters the instrument from the front lens, called the corrector plate. It bounces off a curved primary mirror at the back of the instrument to a secondary spot (a curved, reflective spot on the inside of the corrector plate) and is sent to the eyepiece at the back of the instrument.
There are different variants of the Maksutov telescope, such as the so-called Maksutov-Cassegrain, with slightly different designs.
Most designs rely on a full aperture, the front corrector plate, which is made of glass. With the increase of the telescope diameters, this correct plate becomes larger, heavier, and more expensive to produce.
For these reasons, most commercial Maks do not go past an aperture of 180mm, which, in turn, limits the f-ratio these instruments can have.
What Is A Newtonian Telescope?
Newtonian telescopes (Newts) are reflectors and have the simplest design among telescopes: two mirrors are used to capture and redirect the light towards the eyepiece near the front of the instrument.
Newts have an open tube design with no corrector plate: light simply enters the tube, bounces off the spherical (or parabolic) mirror at the bottom of the instrument to the flat secondary mirror, which redirects the light to the focuser and the eyepiece.
Newts come in different flavors too:
- As an optical tube assembly (OTA)
- Mounted on a rocker box or other alt/az platforms. In this case you are talking about Dobsonian telescopes (Dobs).
- Some Dobs have a truss design, allowing the telescope to collapse to about half its working size for easier transportation and storage.
In all cases, in most Newts the vanes of the support of the secondary mirror will create diffraction spikes on bright stars, something you may or may not like.
What Are The Differences Between Maksutov And Newtonian Telescopes?
As a result of their different designs, Newt and Maks differ in many ways, and here are the main ones:
- Design. Newtonian telescopes use mirrors and for this reason are called reflectors. Maksutov telescopes use a mix of lenses and mirrors and are called catadioptrics.
- Size. Newtonian telescopes are usually larger, heavier, and bulkier than Maksutov telescopes.
- Cost. If we don’t consider things like goto and mounting systems, Newts are cheaper than Maks with equivalent aperture, as their construction is simpler.
- Aperture. Newts can have a diameter up to 400mm or more, while usually the largest Maks in the market clock in at about 200mm in aperture.
- Speed. Maks are often around f/10 or worse, depending on their diameter and focal length. Since Newts often have a shorter focal length and larger aperture, it is not difficult to find them with an f-ratio of f/5 or faster.
- Portability. Maks are much more compact than Newts and often lighter. So they are great portable telescopes. Moreover, Maks hold mirror collimation much better than Newts, so transporting a Mak does not force you to collimate the scope as often as if it was a Newt.
- Cool-down time. Because Newts have open tubes, they have a shorter cool-down time.
One similarity these telescopes share is the presence of a central obstruction from the secondary mirror/secondary spot. The effect of this obstruction on the image is mostly in reducing the contrast with respect to a similar aperture refractor with no central obstruction.
This is quite a technical topic for the type of article I am writing. If you want to know more about this, I suggest you go have a look at this other article.
What Are The Pros And Cons Of Maksutov Telescopes?
Maks are more compact than Newts and can better hold collimation when transported around, which makes them great grab & go scopes. They are also suitable for daylight observations as spotting scopes.
Maks are called planet killers, as they provide a nice sharp and contrasted view and can be paired with almost any type of photographic setup.
On the negative side, Maks are slower than Newts, so observing and photographing deep-sky targets, particularly the faintest ones, will be a struggle. The extremely long focal length also does not play nice with many of the deep sky targets up there, as it results in a very narrow field of view.
High quality focal reducers may be hard to find if they even exist.
Finally, cool-down time can be quite long, something to consider when traveling: the largest Maks can take up to 1hr to acclimate to ambient temperature. Until then, you have turbulent air inside the scope that reduces the optical performances of the instrument.
What Are The Pros And Cons Of Newtonian Telescopes?
Newtonian telescopes (Newts) are also called “light buckets”: for the money, they offer the largest aperture of all telescopes. And a large aperture creates brighter and more detailed images.
Dobsonian telescopes are the simplest “all-in-one” telescopes one can get, and they are perfect for beginners wanting to observe the solar system and the brightest deep-sky objects. High-end models offer a GOTO system to easily find your target.
Newts are often fast telescopes, allowing to gather a lot of light per unit of time, making for better observation and astrophotography. The relatively short focal length of these instruments are perfect for deep sky observation and astrophotography.
Because of their open tube design, Newts cool down pretty fast.
On the negative side, Newtonians and Dobsonian telescopes are not the smallest, lightest, or most portable telescopes you could buy. If you do astronomy and astrophotography on the move, a Newtonian telescope could prove challenging.
Newts are also prone to lose collimation when transported, so you may need to adjust the mirrors’ collimation when you arrive at your location and from time to time.
Being mounted on an alt/az base, dobsons are not the most suitable telescopes for doing deep-sky astrophotography, as they cannot compensate for field rotation, although equatorial bases exist to solve this problem. Still, GOTO dobson on an equatorial base will keep tracking the stars in “steps” rather than continuously as a true equatorial mount would do.
When it comes to astrophotography, a Newt must sit on a strong equatorial mount due to its bulk and weight. Also, the focuser must be strong enough to support the weight of your imaging camera and related accessories.
Unfortunately, most entry-level Newts have flimsy focusers that do not provide enough back focus to let you reach focus with your DSLR or mirrorless camera.
Finally, particularly for astrophotography, fast (low f-number) Newts needs a coma corrector to get round stars in your images.
Newtonian Vs Maksutov Telescopes: Which One Is Best For Beginners?
Both Newts and Maks can be considered beginner-friendly. They both can be purchased equipped with a manual or computerized alt/az base.
This allows for a fast setup and easy framing and tracking, making them a great option to introduce even kids to astronomy.
Small aperture instruments are also quite affordable for both types of telescope.
What Type Of Telescope Is Best For Viewing Planets?
Planets are best observed at high magnification and using large apertures telescopes.
Large aperture telescopes better support high magnifications and keep the image bright enough.
Maks have the edge over Newts and are considered planet killers. They are compact and have a longer focal length than Newts. They also give a more contrasted image thanks to the smaller frontal obstruction.
Going towards the high end of the range, though, we can have Dobsonian telescopes with aperture of 400mm and goto. When properly collimated, high-end Newts can deliver great planetary images.
What Type Of Telescope Is Best For Viewing Deep Sky Objects?
Deep sky targets, such as nebulae and galaxies are huge in comparison to the planets and even the Moon.
More than focal length, what you need is a light bucket to collect enough photons from your target and have a bright image. And for these reasons, Newts are winners over Maks.
A word of caution, though: because of the limits of the human eye, don’t expect to see in the eyepiece what you would see in photographs. Even the brightest objects will appear to you without colors and not as detailed as in photographs.
What Type Of Telescope Is Best For Astrophotography?
Newts are more all-rounder performers than Maks: this is true for visual observation as well as astrophotography, so probably is the best option if you are not focused on planetary and lunar astrophotography.
Again, few words of caution for you:
- Dobsonian telescopes are not great for deep sky astrophotography, and if you want a Newts, you should mount it on an equatorial mount suitable to get the job done.
- Most entry-level Newts can’t focus on a mirrorless or DSLR camera, and the focuser can be rather flimsy. So make sure about the quality of the focuser, and that it can focus on the camera you intend to use.
Newts intended for astrophotography are, for example, those in the PDS series from Sky-Watcher.
Maksutov-Newtonian Telescopes: Get The Best Of Two Worlds
Maksutov-Newtonian (MN) telescopes like the Sky-Watcher MN 190/1000 have a hybrid design resulting in a Newtonian telescope with a corrector plate as used in Maks and are very performant.
MN telescopes are a lot like apochromatic refractors and deliver sharp views, wide, flat fields, and the ability to hold up to planetary magnifications.
The close tube design also protects the mirrors from dirt and scratches at the cost of increasing the cool-down time of the instrument.
They are very versatile telescopes, often cheaper than high-end apochromatic refractors with large apertures.
While both types of telescopes can be affordable, user-friendly, and can deliver great images, if you prefer exploring the Solar System, a large aperture maksutov will serve you well.
Newtonian telescopes are more versatile and are true all-rounder performers, allowing you to explore the Solar System, as well as the deep sky.