I'm thinking of buying a 6'' Dobsonian telescope.?

Question

What exactly is 6'' on it? Is it the front opening that lets all the light in? in other words, is 6'' the width of the front opening?

Answer 1

6 inches is the diameter of the primary mirror. The opening itself is slightly over 6 inches to accomodate the mirror.

Performance is directly proportional to the area of primary mirror (assuming quality is consistent). A 6 inch diameter telescope would gather 4 times as much light as a 3 inch diameter telescope.

The more light you can gather, the higher magnification you can use effectively. You can theoretically get the same magnification out of a smaller scope, but the light would be much dimmer and the image much poorer.

With a 6 inch Dobsonian, you would be able to see Jupiter with cloud belts and its moons, Saturn and its rings, and some deep space objects such as nebulae.

The drawback to the Dobsonian is that it uses a simple azimuth mount. The telescope can move up and down and side to side. This makes it easy to aim the telescope, but the telescope would not be able to track the object during the Earth's rotation. If you want astrophotography then you need an equatorial mount(which is a little more difficult to use) and a tracking motor.

You will be surprised how fast an object moves out of view due to the Earth's rotation.

Answer 2

Actually, 6"is stand for : it denotes the size of the primary mirror.Ya .That is the width of the front opening (6"=apprximately15 cm) ok


Dear friend,u don't need to buy it.Ya.I will give u the details, that how to build this telescope.ok
so try it and do this

Building a 6" Dobsonian Telescope Project


When I was invited to join the telscope building class I was so excited. I received a list by email of some things I might need during the class, in addition to the items pictured below I would also bring the following items.
an electric Drill
an obital sander
safety goggles
#2 Phillips Head, #2 Square head for deck screws
a putty knife for bondo
wood glue, and rags
a 1 inch, 2 inch paint brushes
a small 3 inch paint roller
a ruler, tape measure, and square
Spar Urethane clear matt finish type
sand paper 60 grit, 120 grit and 240 grit.
a Dremel (if you own one)
a pencil & compass for angles
a small Scroll saw, & set of small files (if you want to do fancy details.) With those tools in hand you should be ready to begin.

Answer 3

A 6inch dobsonian is an excellent all-around telescope.

6inches refers to the size of the light gathering primary mirror. The opening of the tube will be somewhat larger, as there is a little space between the mirror and the tube sides.

I've included some general information links below. You may also want to look around the Beginner's forum on the Cloudynights.com website.

Answer 4

That is the aperture size. That is the opening that allow the light to enter.

Answer 5

On a refractor telescope it is the lens diameter, on a reflector it is the diameter of the mirror.

Answer 6

Yes but the focal length determines the resolution