Hi guys, recently i bought a dobsonian 8" skywatcher
I've been trying to star gaze through the eyepiece but seems like it's quite hard to do so. The image is so blurred. I've read the manual that we have to let the temperature of telescope stabilized with the outside's temperature first for half an hour and I've did that. Besides, during the day, I try to check the finderscope and the eyepiece lens. Finderscope works excellent but it's still a no for eyepiece.
The question: may I know what can cause the eyepiece to display such blurred image? Is it because the disturbance of air in the tube? Because lately it has been quite windy in my place. Or perhaps because of other reasons.
Besides,can u give any advice/tips how to use dobsonian for the first time. Perhaps u can share how to take care of it (the manual just give the simple one). Thank u so much
Hi and welcome Eeda
Sounds likely that you still have the 2in eyepiece holder still behind the 1,25 adapter , undo the 1,25 screws then there's two more screws undo them and you should have what looks like a barrel take that out and now put the 1,25 there, leaving out the 2in adapter should focus now
I believe David is correct.
It is a very common mistake with Skywatcher DOB (first time) users.
It comes with an adapter for 2" eyepieces and standard 1.25" eyepieces.
(Unfortunately on newer models) the 1.25 adapter fits into the 2" adapter and looks like it belongs that way.
It does not, only use one at a time.
Remove the 2" adapter (as the supplied eyepieces are normally only 1.25).
Using both together moves the focus point beyond the range of the focuser.
You have chosen a great telescope and it should give you amazing views.
Another hint, always start with the lower magnification eyepiece( the one with the larger number in mm on it) - (probably 20mm or 25mm).
Then move up to the higher magnification (probably a 10 or 12 mm).
Note that this will require a little focus adjustment.
Hi and welcome Eeda
Sounds likely that you still have the 2in eyepiece holder still behind the 1,25 adapter , undo the 1,25 screws then there's two more screws undo them and you should have what looks like a barrel take that out and now put the 1,25 there, leaving out the 2in adapter should focus now
David
I see...I thought we have to put both holders (silly me) ...But the image is still blur (but better than before). Well, is it possible the image is blurred because my target is near (less then 500m)..Since my backyard is quite small, I just pointed my telescope towards any tree/house near to my house. I should try to point towards moon but now it's waning crescent and it's rise quite late nowadays.
I believe David is correct.
It is a very common mistake with Skywatcher DOB (first time) users.
It comes with an adapter for 2" eyepieces and standard 1.25" eyepieces.
(Unfortunately on newer models) the 1.25 adapter fits into the 2" adapter and looks like it belongs that way.
It does not, only use one at a time.
Remove the 2" adapter (as the supplied eyepieces are normally only 1.25).
Using both together moves the focus point beyond the range of the focuser.
You have chosen a great telescope and it should give you amazing views.
Another hint, always start with the lower magnification eyepiece( the one with the larger number in mm on it) - (probably 20mm or 25mm).
Then move up to the higher magnification (probably a 10 or 12 mm).
Note that this will require a little focus adjustment.
Enjoy, and keep asking questions.
Thank you for the information ! There are lot of things I don't know about this telescope and I'm glad if you guys can help me! It's so fun to explore this telescope and night sky of course.
Mine was supplied with 25mm and 10mm. How those two may differ?
I see...I thought we have to put both holders (silly me) ...But the image is still blur (but better than before). Well, is it possible the image is blurred because my target is near (less then 500m)..Since my backyard is quite small, I just pointed my telescope towards any tree/house near to my house. I should try to point towards moon but now it's waning crescent and it's rise quite late nowadays.
Pointing at a close tree definitely wont help, it is too close! You really need to point it skyward. As the Moon will probably not be high enough to try until later in the week, why not try pointing it at Jupiter, the really bright "star" about half-way up in the north at sunset? You should see the big disc of the planet and the 4 Galilean moons around it. Focus the moons to pin points (or as close as) and then if Jupiter is still a bit fuzzy or blurry that is the local atmosphere moving about, but you should at least see two stripes across it, which are the main equatorial belts.
I'm so sorry for being inactive these past weeks..I've been busy with my examinations and university life.
Quote:
Originally Posted by Blue Skies
Pointing at a close tree definitely wont help, it is too close! You really need to point it skyward. As the Moon will probably not be high enough to try until later in the week, why not try pointing it at Jupiter, the really bright "star" about half-way up in the north at sunset? You should see the big disc of the planet and the 4 Galilean moons around it. Focus the moons to pin points (or as close as) and then if Jupiter is still a bit fuzzy or blurry that is the local atmosphere moving about, but you should at least see two stripes across it, which are the main equatorial belts.
I've take a look at jupiter. That is soo awesome!! It's really beautiful! . So the tiny,shiny 'dots' (through the eyepiece) surrounding jupiter are the Galilien moons?? Wow!
What else can I see/explore with my dobsonian 8"? *truly excited*
Last night, I spent most of my time with my telescope. Yup, the night sky is totally awesome through the eyepiece. Even my friends were excited when I showed them the moon and jupiter though. Lol, it's the time to influence them to like astronomy
Here is my first,best moon picture taken last night (others are not good). It's quite hard to take this picture through dobsonian and I was told dobsonian is not suitable for astrophotography. Nevertheless, I'm very satisfied with it!
Hi Eeda,
welcome back.
Before buying a moon filter, if your dust cover has a small removable cap, try viewing the moon with the dust cover on (with the small cap removed).
Make sure to position this away from the spider veins (that hold the secondary mirror).
This should cut down the light significantly, while still allowing good viewing.
Also works for Jupiter when it is bright.
If this is not sufficient, you can buy a moon filter, or a NULL filter (which just cuts down light transmission) or a polarising filter arrangement (which is two polarised filters, which you can turn in respect of each other to adjust the amount of light that gets through).
Other things to look at currently may include Eta Carina (nebula), Omega Centauri (Globular cluster), The Jewel Box (Open cluster with various coloured stars); Centaurus A (Galaxy - The Hamburger).
These are all deep Southern objects around the Southern Cross (Crux).
I'm so sorry for being inactive these past weeks..I've been busy with my examinations and university life.
I've take a look at jupiter. That is soo awesome!! It's really beautiful! . So the tiny,shiny 'dots' (through the eyepiece) surrounding jupiter are the Galilien moons?? Wow!
What else can I see/explore with my dobsonian 8"? *truly excited*
there is plenty to see, just pan around and discover. that's the beauty of a dob, you can do that with ease.
planets are good to wow friends with and so are clusters. especially globular clusters like omega centauri which is in a good position at the moment and getting better as winter moves in. open clusters are good too .. infact the whole sky is good
the moon can be your friend with bright objects like solar objects like the moon and some planets, and clusters .. but is your enemy for faint fuzzies like galaxies and nebulae.
Hi Eeda,
welcome back.
Before buying a moon filter, if your dust cover has a small removable cap, try viewing the moon with the dust cover on (with the small cap removed).
Make sure to position this away from the spider veins (that hold the secondary mirror).
This should cut down the light significantly, while still allowing good viewing.
Also works for Jupiter when it is bright.
If this is not sufficient, you can buy a moon filter, or a NULL filter (which just cuts down light transmission) or a polarising filter arrangement (which is two polarised filters, which you can turn in respect of each other to adjust the amount of light that gets through).
Other things to look at currently may include Eta Carina (nebula), Omega Centauri (Globular cluster), The Jewel Box (Open cluster with various coloured stars); Centaurus A (Galaxy - The Hamburger).
These are all deep Southern objects around the Southern Cross (Crux).
Ahh..it works! It's not too bright when I viewed moon..So I believed I don't need to buy the moon filter. So, the function for the small hole at the removable cap is to cut down the light transmission?
Btw, but how do guys easily managed to spot the stars/clusters in the finderscope (n of course the eyepiece later on). Last night, I tried to take a look at The Jewel Box as I read at the wiki that it's easily spotted once u find the Beta-Crucis. But I got trouble to find the Crux itself inside the finderscope although I can spot its location with my naked eyes. When I viewed the sky with the finderscope, there are lot of stars and I can't spot the Beta-Crucis. Easily lost in the midst of stars
there is plenty to see, just pan around and discover. that's the beauty of a dob, you can do that with ease.
planets are good to wow friends with and so are clusters. especially globular clusters like omega centauri which is in a good position at the moment and getting better as winter moves in. open clusters are good too .. infact the whole sky is good
the moon can be your friend with bright objects like solar objects like the moon and some planets, and clusters .. but is your enemy for faint fuzzies like galaxies and nebulae.
enjoy your scope
matt
I wonder how the clusters look. I've been pointing my scope towards the southern sky and yup, it's breathtaking scenery . But I don't know how to look at a specific clusters (easily lost by the trillion of stars).
The small dust cap is primarily meant for solar work to avoid heat build up in the optical train, which can be destructive. The sun is so bright that
the small aperture doesn't matter.
What you are experiencing with trouble locating clusters, is exemplified by what happens when at a dark site. There are so many stars visible that
the familiar patterns get swamped. The best thing to do is learn some of
the sky using low power binoculars. 7x at most. It takes quite a while to
become thoroughly familiar with the night sky.
raymo
Dobsonian 8"
! There are lot of things I don't know about this telescope and I'm glad if you guys can help me! It's so fun to explore this telescope and night sky of course.
. But I don't know how to look at a specific clusters (easily lost by the trillion of stars).
