A Conversation for Ask h2g2
Dobsonian Telescope
Llama Sabachthani Started conversation Nov 12, 2004
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
Gnomon - time to move on Posted Nov 12, 2004
It sounds like it was named after someone called Dobson.
Dobsonian Telescope
WanderingAlbatross - Wing-tipping down the rollers of life's ocean. Posted Nov 12, 2004
Apparently a John Dobson
http://encyclopedia.thefreedictionary.com/Dobsonian
Dobsonian Telescope
Metal Chicken Posted Nov 12, 2004
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
Llama Sabachthani Posted Nov 12, 2004
So it is the type of mount that makes them Dobsonian. That explains it. Thank you very much.
Dobsonian Telescope
winnoch2 - Impostair Syndromair Extraordinaire Posted Nov 12, 2004
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 pole).
Dobsonian Telescope
Gnomon - time to move on Posted Nov 12, 2004
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
winnoch2 - Impostair Syndromair Extraordinaire Posted Nov 12, 2004
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?
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.
Key: Complain about this post
Dobsonian Telescope
- 1: Llama Sabachthani (Nov 12, 2004)
- 2: Gnomon - time to move on (Nov 12, 2004)
- 3: WanderingAlbatross - Wing-tipping down the rollers of life's ocean. (Nov 12, 2004)
- 4: Metal Chicken (Nov 12, 2004)
- 5: Llama Sabachthani (Nov 12, 2004)
- 6: winnoch2 - Impostair Syndromair Extraordinaire (Nov 12, 2004)
- 7: Gnomon - time to move on (Nov 12, 2004)
- 8: winnoch2 - Impostair Syndromair Extraordinaire (Nov 12, 2004)
More Conversations for Ask h2g2
- For those who have been shut out of h2g2 and managed to get back in again [28]
3 Weeks Ago - What can we blame 2legs for? [19024]
Nov 22, 2024 - Radio Paradise introduces a Rule 42 based channel [1]
Nov 21, 2024 - What did you learn today? (TIL) [274]
Nov 6, 2024 - What scams have you encountered lately? [10]
Sep 2, 2024
Write an Entry
"The Hitchhiker's Guide to the Galaxy is a wholly remarkable book. It has been compiled and recompiled many times and under many different editorships. It contains contributions from countless numbers of travellers and researchers."