If you as a beginner want a big aperture telescope for minimum cost. Then without thinking too much you should go for the Dobsonian-type telescope. As a beginner when you start looking for telescopes you come across so many different types of telescopes. These different types most of the time end up confusing you. In this scenario, choosing the right telescope feels like a very difficult task. If you are in such a dilemma then without thinking too much you can buy a medium-sized Dobsonian telescope. So today in this article we will tell you the advantages and disadvantages of the Dobsonian telescope.
Dobsonian telescopes are simple and easy-to-use telescopes. They were first designed by John Dobson in 1965. One of the best telescopes for beginners is the Dobsonian telescope.
The Dobsonian telescope’s optical tube assembly is of reflector type. When you point this telescope to a celestial object, it collects the light from that object through its aperture. This collected light travels through the optical tube to the primary parabolic mirror. This mirror reflects light to the secondary mirror. It is then transmitted to the eyepiece, where you can observe the celestial object.
The mount of these telescopes is very sturdy. It has a solid base on which a rotating box is fixed. The whole optical tube assembly sits at the top of the box. The bearings allow smooth movement, up and down. The box itself rotates on the sturdy base giving the left-right movement to the telescope. This mount is an alt-az mount. While observing an object you should make sure that the base is properly leveled on the ground.
Let’s see some of the advantages of the Dobsonian telescopes.
It has a Big Aperture.
Aperture is the main criterion when buying a telescope. When a telescope has a bigger aperture, then it can collect more light. Collecting more lights means the images you will see are sharper and clearer. Dobsonian telescopes offer bigger aperture at a very affordable price. Dobsonians are reflector-type telescopes. So, the optical tube assembly of Dobsonian telescopes is of mirrors instead of glass. Because of this, they are cheaper to manufacture compared to the refractors and Schmidt-Cassegrain-type telescopes.
They are very easy to use.
The Dobsonian telescopes are very easy to set up. All you have to do to set up a telescope is to put the mount on a flat leveled surface. Attach the optical tube assembly to the mount. Select your eyepiece and point the telescope to the object you want to observe.
Before the smartphone era. You would require a really good computerized telescope which has all the data of the celestial objects for finding a celestial object in the sky. In those days finding the celestial object would be a time-consuming process for simple non-computerized telescopes. But nowadays everyone has a smartphone and you can download some astronomy apps to locate an object. By the way, if you want to know which astronomy apps are best, then check out this article on TheAlienTech.com. With a simple telescope and these astronomy apps, you can easily find the celestial objects you want. It will reduce your time of finding the objects in the sky.
No image distortion
The Dobsonian telescopes do not distort the image or you will not find any aberrations in these telescopes. The mirror collects light from an aperture. Then reflects it back to one point at the same time, giving you a clearer, sharper image. This is not the case with other types of telescopes that uses glass or lenses.
They are very cost-effective
One of the reasons these telescopes are popular is because of their cost-effectiveness. You can get the big aperture Dobsonian at a very cheaper price. As mentioned earlier the optical tube assembly of Dobsonian uses mirrors, so overall it’s cheaper to manufacture the telescope. The mount of the telescope is also not very expensive to make. It has very minimum parts. If you are someone who is into “do it yourself(DIY)” stuff then you can easily make this mount at home. Cost is one of the major factors when buying a telescope. So, this is one of the biggest advantages a Dobsonian telescope has.
Dobsonian too has some disadvantages.
It requires collimation.
When you play the guitar occasionally you have to tune it to get the best sound from it. The same is here with the Dobsonian telescope. You will need to collimate or in other words adjust the mirrors to get the best performance. This is not that difficult if you have a collimator. This is not that big of a disadvantage.
They are heavy
It is fact that they have a long tube and a very sturdy base. So they get much heavier with the increase in
aperture size. Dobsonian telescopes are heavier when compared with the other types of telescopes. When your telescope is heavy, it is difficult to take it to a different stargazing location.
Not good for astrophotography.
Dobsonian mounts are alt-az mounts. These mounts are not suitable for astrophotography. In astrophotography, you need long exposure shots. So, you need the object in your field of view all the time. Which is very difficult with the manual alt-az mount. To understand the concept behind this, click here.
Overall Dobsonian telescopes are good for beginners who just want to observe the night sky. As a beginner, you shouldn’t invest a lot of money in a telescope. So buying a 6 to 8-inch Dobsonian telescope is a perfect choice. This 6 to 8-inch Dobsonian will cost you around $400 – $700. When you compare it with the other types of same aperture-sized telescope, then it will cost you more than $1000. So money and performance-wise Dobsonian is the best telescope for beginners.
