The Official Astronomy Thread

[Crusader]

You'll need a tracking platform, definitely an EQ version for astrophotography. Don't know of any local sources though. Might be an option to get a EQ mount and add your OTA useing tube rings, but then it's not a dob and the focuser will go all over the place.

 

[Kalvaer]

Optical Encoders, Its obviously more complicated than just that, but there are a few programs and guides on the net. Some of them Free, Some not.

Check this out http://www.wildcard-innovations.com.au/kits/pn-dob-sw-spec_describe.html

 

[mercurial]

You'll need a tracking platform, definitely an EQ version for astrophotography. Don't know of any local sources though. Might be an option to get a EQ mount and add your OTA useing tube rings, but then it's not a dob and the focuser will go all over the place.

I've heard of wedges as well. It looks like a costly procedure and the Dob is so big which is why I want something more portable.

 

[mercurial]

Optical Encoders, Its obviously more complicated than just that, but there are a few programs and guides on the net. Some of them Free, Some not.

Check this out http://www.wildcard-innovations.com.au/kits/pn-dob-sw-spec_describe.html

I'm a bit confused. Is that like a goto system? So then I'll just need a wedge/mount. Thanks for that.

 

[Sparky_za]

Just want to say thank you for all the replies and advice guys. I will definitely be giving this some serious thought. Just need to make sure I'm going to make it to the end of this very long month... hehehe...

Oh, one last thing. Are the different styles down to personal preference, or does one offer advantages over the other?

 

[mercurial]

Just want to say thank you for all the replies and advice guys. I will definitely be giving this some serious thought. Just need to make sure I'm going to make it to the end of this very long month... hehehe...

Oh, one last thing. Are the different styles down to personal preference, or does one offer advantages over the other?

Well there are 3 types of telescopes - reflectors, refractors and catadioptrics. Reflectors uses mirrors, refractors uses a lens and catadioptric (cassegrains) uses both mirrors and lenses and generally provide sharper views on lunar and planetary observations. Then there's the new and improved refractor, called the apochromatic refractor. The ordinary and older refractor type is the achromatic. The difference is that the apo it has colour correction and reduces chromatic aberration. They are very expensive and is very small in terms of aperture, but the images are crystal clear.

 

[Crusader]

See if you can find the Telescope thread go Off Topic (sorry can't link no my cell) and go through it. Most of the pros/cons of each type where discussed there.

 

[Sparky_za]

Ok, I will have around R6k to spend on a scope. I've had a look at that site and see there are quite a few options. If you guys were spending the cash, what would you get and why? Not looking for you to make my decision, but it's always nice to see what everyones and experience is.

 

[marine1]

Guys need some help, setting up my scope again from scratch with the "GOTO", do you point in a "SOUTH" direction being in the souther hemisphere or in a northern direction?
Thanks so much.

 

[Crusader]

Guys need some help, setting up my scope again from scratch with the "GOTO", do you point in a "SOUTH" direction being in the souther hemisphere or in a northern direction?
Thanks so much.

My best advice would be to read the manual. If it's an EQ mount then chances are that you need to point to the South Celestial Pole. If it's a mount similar to the Celestron and Meade Goto mounts then I think you just need to point it to the North and do the 2/3 star align procedure.

 

[marine1]

It is an EQ3 mount and I have been pointing North - maybe thats the problem, Took the whole thing apart and started from scratch. Although the GOTO does give 1,2,3 star alignemtns options.
Thanks

 

[Crusader]

Ok, I will have around R6k to spend on a scope. I've had a look at that site and see there are quite a few options. If you guys were spending the cash, what would you get and why? Not looking for you to make my decision, but it's always nice to see what everyones and experience is.

Well, my choice would be the Orion XT8 8" Classic for R4470 (+R380 shipping). Just make sure if they have stock and that it is the older classic line which comes with the 2 eyepieces and optical finderscope. Orion economized the classic line recently replacing the accessories that come with the scope. On the "new" classics you only get one eyepiece and a red dot finder.

That should give you more than enough aperture to view most objects and will leave enough of your budget over for some accessories.
Definitely get a red LED flashlight or headlamp, a 2x Shorty Plus barlow (R750) and a Red dot finderscope (the Skywatcher works ok for R190).

This of course assumes that you have enough space available to store the dob and that you don't have to move it up and down stairs constantly.

 

[Crusader]

It is an EQ3 mount and I have been pointing North - maybe thats the problem, Took the whole thing apart and started from scratch. Although the GOTO does give 1,2,3 star alignemtns options.
Thanks

As I said I don't have any experience of GoTo scopes aside from what I've read. I know the Alt-Az versions only need you to point it in a North direction (at least some do).

With EQ I'd definitely guess that you need to point to the SCP and make sure that it's set up for your latitude.

 

[Sparky_za]

Well, my choice would be the Orion XT8 8" Classic for R4470 (+R380 shipping). Just make sure if they have stock and that it is the older classic line which comes with the 2 eyepieces and optical finderscope. Orion economized the classic line recently replacing the accessories that come with the scope. On the "new" classics you only get one eyepiece and a red dot finder.

That should give you more than enough aperture to view most objects and will leave enough of your budget over for some accessories.
Definitely get a red LED flashlight or headlamp, a 2x Shorty Plus barlow (R750) and a Red dot finderscope (the Skywatcher works ok for R190).

This of course assumes that you have enough space available to store the dob and that you don't have to move it up and down stairs constantly.

Thanks, I will take that into consideration

 

[nimthor]

Marine1,

You need to have its home position point to the celestial south pole. I guess there will be an option somewhere on the menu where you put your location it, should realise you are in the southern hemisphere. I have the Meade LXD75 goto. Did you take the mount apart do do a re0grease jobbie?

Clear and windless skies!
Charles

 

[marine1]

Um not sure about that, It is a kit. The goto does not ask which hemisphere you are in though.

 

[Sparky_za]

Well, my choice would be the Orion XT8 8" Classic for R4470 (+R380 shipping). Just make sure if they have stock and that it is the older classic line which comes with the 2 eyepieces and optical finderscope. Orion economized the classic line recently replacing the accessories that come with the scope. On the "new" classics you only get one eyepiece and a red dot finder.

That should give you more than enough aperture to view most objects and will leave enough of your budget over for some accessories.
Definitely get a red LED flashlight or headlamp, a 2x Shorty Plus barlow (R750) and a Red dot finderscope (the Skywatcher works ok for R190).

This of course assumes that you have enough space available to store the dob and that you don't have to move it up and down stairs constantly.

Is the reason you mention stairs because it takes a long time to setup the scope, or because the Dob's are more fragile than other scopes? I have never looked at a Dob before, so please excuse my ignorance.

 

[Albereth]

Hmm - I read through this entire thread and decided to join in the monthly challenge thingy. So I have armed myself with the Jan star maps and my binos and as soon as the moon wanders off and takes the clouds with it I'll give Orion's Nebula a bash.

I can't believe that I was studying astronomy 20 years ago. It was hordes of fun and had lots of maths as I recall.

I did start making a telescope - spent many hours grinding glass but didn't get much further than that. I still have the two pieces somewhere but the mess involved in the process limited the activity. Women! LOL. Does anyone know if someone will 'finish' the process for me? There was a club of sorts that met at Parktown Boys.

Does anyone have any info on when the observatory is open to the public? It used to be on a Friday night when there wasn't too much moon.

 

[mercurial]

Is the reason you mention stairs because it takes a long time to setup the scope, or because the Dob's are more fragile than other scopes? I have never looked at a Dob before, so please excuse my ignorance.

A Dob requires some manpower to move around. Other than that, they are good scopes. There is no setup required for Dobs. You just take it out, let it cool down for a while and you can start looking.

 

[Crusader]

@Sparky_za: A dob has minimal setup time. I carry mine in two parts - the mount and optical tube (OTA). All you need to do is place the mount on the ground. Place the OTA on the mount and give the scope around 30 to 40 mins to reach ambient temperature. Then you are all set to start observing.

The reason I mentioned stairs is that the OTA can ad slightly unwieldy and awkward to move around. Imagine carrying a tube 1,2 meters long and the width of 1.5 or 2 coffee cans or a large paint can - without bumping it, and you'll get a rough idea. It's definitely not difficult and you get used to it very soon, but if you have to in up and down stairs you might find that you won't take the scope out quite as often.