A Conversation for Ask h2g2

Dobsonian Telescope

Post 1

Llama Sabachthani

When looking at descriptions of astronomical telescopes, many of them are described as 'Dobsonian'. I do not know what does this mean and would like to to know.


Dobsonian Telescope

Post 2

Gnomon - time to move on

It sounds like it was named after someone called Dobson.


Dobsonian Telescope

Post 3

WanderingAlbatross - Wing-tipping down the rollers of life's ocean.

Apparently a John Dobson

http://encyclopedia.thefreedictionary.com/Dobsonian


Dobsonian Telescope

Post 4

Metal Chicken

Dobsonian telescopes are a type of Newtonian reflecting telescope, on a simple mount that makes them fairly portable, easy to set up and favoured by those who want to go to the effort of grinding and polishing mirors to make their own telescopes. They're named after a guy called John Dobson who was well known for building this type of telescope and helped popularise the activity of DIY telescopes and astronomy generally.
Does that help?
MC


Dobsonian Telescope

Post 5

Llama Sabachthani

So it is the type of mount that makes them Dobsonian. That explains it. Thank you very much.


Dobsonian Telescope

Post 6

winnoch2 - Impostair Syndromair Extraordinaire

Also, due to the fact that much of the cost of a telescope is in its mount, when you use the simpler design of the dobsonian, you can buy a larger aperture reflector for your money, than you could with other types of mount.

On the other hand, Dobs are harder to track with- i.e. due to the alt-azimuth (up/down/left right)movement of the mount, it can be a bit fiddly to keep an object centred in the eyepiece (unless you live at the equator or the north/south polesmiley - smiley).


Dobsonian Telescope

Post 7

Gnomon - time to move on

They should be good for looking at star fields, nebulas and clusters then, where low magnification and high light gathering are needed; and not so good for looking at planets where high magnification is needed.


Dobsonian Telescope

Post 8

winnoch2 - Impostair Syndromair Extraordinaire

Pretty much, yeah. Though i dare say you can buy some pretty long focal length versions that would have a higher focal ratio. In fact i don't see any reason why you couldn't build a dobsonian mount for any design of telescope. A Dobsonain Smidt Newtonian cassegrain anyone?smiley - silly

But i don't think any major manufacturer has bothered, as most people prefer the accuracy and ease of use that an equatorial mount or a computer controlled mount offers.


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