10" Dobsonian

[Maged]

Hi All,

I will be getting my new 10" dobsonian this Saturday, as an upgrade from 4" refractor. I am so excited about it, so can you please give me your recommendations about objects to see in my first day of using it in a light polluted area?

Thanks

[Astro Imp]

The clusters around Cassiopeia might be good place to start at this time of year.

There are just so many objects viewable with your new scope, have a great time.

I will be interested to read your impressions as I keep dithering about upgrading myself and a 10" Dob is on my wish list.

Good luck and clear skies.

[laudropb]

There are lots of Globs and open clusters viewable at the moment. If you are going to look for DSOs I would advise you get filters. UHC and OIII make a difference on nebulae and depending on the source of your LP a LP filter can help.

[Maged]

There are lots of Globs and open clusters viewable at the moment. If you are going to look for DSOs I would advise you get filters. UHC and OIII make a difference on nebulae and depending on the source of your LP a LP filter can help.

can you give me recommendations about filters as I am confused about what's the right filter for which object?

[Maged]

The clusters around Cassiopeia might be good place to start at this time of year.

There are just so many objects viewable with your new scope, have a great time.

I will be interested to read your impressions as I keep dithering about upgrading myself and a 10" Dob is on my wish list.

Good luck and clear skies.

 Will do let you know about my first impressions

[NGC 1502]

can you give me recommendations about filters as I am confused about what's the right filter for which object?

A long read but worth it - http://www.prairieastronomyclub.org/resources/by-dave-knisely/useful-filters-for-viewing-deep-sky-objects/

HTH, Ed.

[Gazabone]

Very good choice, you'll love the extra detail you'll be able to see. To start with it might be good to revisit the objects you've already looked at, you'll probably be blown away.

Happy viewing.

[spike95609]

Have a look for globular clusters. M13 in Hercules above all else. Light pollution or not it's an incredible sight.

[estwing]

Save your money don't get any filters yet just take it to darker skies..

[Charic]

Don't buy filters ?

Just use the scope as it is, in its basic form and see how it deals with the light pollution. Try to find M31 Andromeda.

Then when you think , well, maybe not so good after all, considering this is a 10" reflector, and every Dob owner raves about them, try the scope in its same basic form but this time from a dark site and just be prepared for the difference you will see? 

These scopes are good, very good, but respect the local conditions. I love my scope, only 8" ( next would be a 12" ) but this scope is just totally different at a darker site using the basic eyepieces ( no street lights or city glow) , just imagine what its like when you start introducing better than the supplied optics, to give yourself a better field of view and possibly more eye relief. 

[MartinB]

Don't forget about the solar system. Although it might not be designed primarily for planetary viewing, on nights of good seeing you will get some great high resolution views.

[estwing]

yes don't buy filters get to dark skies first...

[John]

I agree that globular clusters are a great way to try out your larger aperture scope. There are plenty of them and they respond to an aperture increase perhaps more than any other type of deep sky object. A 10" scope will show  the brighter  globular clusters resolved in their outer regions and quite far into their cores into 1000's of stars. There is an excellent globular cluster in Pegasus called Messier 15. It's quite well positioned at the moment   

[Maged]

Thanks everybody for all the useful information

[Mrbloke]

I too would skip the filters for now. I have moderate light pollution and am struggling to get use of the UHC and OIII filters that I have. For example, I can barely see the veil nebula from my house. But when I view from a dark site, and wow.

I am hoping Orion will be improve when it becomes available at a more reasonable time of day.

I agree that I would be looking at andromeda, the double cluster and all around Cassiopeia, M57 ring, M13 great glob. M15 is well placed for me too with M2 just below it.

[Maged]

I have a regular CLS light pollution filter and I didn't find it that much useful with the 4" refractor. All it does is to turn the colours blue !

[Phil Fargaze]

Don't forget about the solar system. Although it might not be designed primarily for planetary viewing, on nights of good seeing you will get some great high resolution views.

Exactly what I was going to say, I`ve had some great views of the planets with my 10" dob. From Mercury right out to Neptune.

[Maged]

I got my scope yesterday. and I really felt the upgrade from 4" refractor when I observed M31 and M42. I also tried some double stars and the moon. But as I am new to reflectors, I believe it was not perfectly collimated, I will share my experience and please tell me if that was a collimation issue or optics issue which I hope it is not.

I was using 46X to try some double stars and M42, but I noticed that I can not achieve perfect focus as objects were having tiny shadows and stars were having small trails at the center of the FOV. and definately I couldn't separate the 4 trapezium stars in M42.

Then I tried a higher power 88X that's when things became really out of focus even the moon was looking so funny!

Is that because of collimation? I hope so, as I didn't collimate it when I started my night yesterday as when I looked at the seconady morror from where you place the eye piece I noticed that the point was inside the circles so I thought it was collimated.

Please let me know cause I'm worried if that's an issue with the optics?

Thanks

[Charic]

I dont think there is an issue with the mirrors themselves, but a full collimation check will ensure they are properly aligned. Check out astro babys guide.

Chek that the focuser friction is smooth, there is an adjuster under the focus wheels on the centre plate.

Collimate during the day, Star test at night. If/when the airy disk is concentric, you wont get/need any better with further collimation.

Any other effects should just be down to the seeing conditions, or maybe an eyepiece not suitable to your needs.

Keep at it.

[NGC 1502]

Was the scope fully cooled ?   If it is kept indoors, especially in a warm room, it can easily take an hour or so to cool to the outside temperature for a 10".

To speed up cooling, if you can store the scope in an outbuilding or an unheated room indoors that would help, as would removing the front dustcap after setting up.

At 46x and 88x the 4 trapezium stars in M42 should be very easy to see in most scopes.

If you are still getting poor views when the scope is cooled, could be poor seeing ( turbulent atmosphere ) or a collimation issue.

Poor mirrors are unlikely, most of the reflectors on sale these days have good to excellent mirrors.

Hope you sort it, Ed.

[Phil Fargaze]

I would go with cooling too. I keep my 10" outside in the obsy to reduce the effects of tube currents with a warm mirror.

[AndyWB]

Was the focusser actually moving? Check that the focus lock was off - otherwise the focusser knobs go round, but focus doesn't change...  It's a screw knob on the bottom of the crayford.

The 10" should split the trapezium with ease. With mine, which is nothing special, I've seen the E and F stars of the Trapezium too.

[niallk]

Perhaps check for pinched optics (do a quick Google - mirror clips could be tight for transport from a factory).

+1 for Astro Baby's great guide to collimation, and Moonshane here also has a great guide, also Andy's shot glass site. I find reading several descriptions very useful.

The best thing I ever did was mess up my collimation so badly that I feared I could never get the scope to work again! It made me really study these guides, and take the time to understand how to align the secondary (hardest part), and after that it was not so daunting I'm very indebted to the authors of these guides.

http://stargazerslounge.com/topic/197640-collimation-and-star-hopping/

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

http://www.andysshotglass.com/Collimating.html

If you wrack the focusser do you see a transition from very blurred through more 'focussed' and blurred again?

I get away with collimating my 10" Skywatcher in the day time, with a cheshire, and (don't tell anyone) I don't actually collimate this scope in the dark!

I'd normally give my scope >45mins cooling outside with the dustcap off if I'm looking at high power planets/moon - or not so strict if looking at lower power DSOs.

Best of luck,

-Niall

[Maged]

Was the focusser actually moving? Check that the focus lock was off - otherwise the focusser knobs go round, but focus doesn't change...  It's a screw knob on the bottom of the crayford.

The 10" should split the trapezium with ease. With mine, which is nothing special, I've seen the E and F stars of the Trapezium too.

The focusser was actually moving so I had space to move it before and after the best focus point I could achieve (which was distorted). 

[Maged]

I wanted to ask about whether the star distortion I saw yesterday was a collimation error or optics default?

first of all I still don't have any collimation tools, so I collimate using only my eyes till I buy a new Cheshire tool.

I reached a point yesterday that when I use a low magnification eyepiece and de-focus a star I find the star becomes nearly a small line, when I de-focus the other way around the line changes direction by 90 degrees. 

when I reach the best focus I can get the star is having a cross like extensions and I don't feel that the image is that sharp.

I know I have to work more on learning to collimate, but I wanted to know if that distortion is a collimation issue in the first place?

Thanks