A few questions

[Filcon (Phillip)]

Hi to all members reading this thread. I have been interested in reading many of the threads by beginners on this forum and have gained a lot of insite so far. I guess I would have to say I'm not far from being a beginner myself, although I did purchase an el' cheepo Tasco 100mm reflector back during the Halley's Comet appearance in the 80's. I have since used the scope on occasions and thoroughly enjoy the pastime, but by no means do I consider that I have great knowledge on the subject. It is getting to the time that I would like to purchase something with a lot more muscle, so have been doing a lot of reading to increase my knowledge of where amateur astronomy is at today.

I do have a number of questions that come to mind, but I will tackle them one at a time so as to not become too confused. Can someone help me with the way that a Dob. is used to manually track? I seem to imagine it could be a little difficult at higher magnification unless there is some sort of hand tracking gearing to help with this. Am I beating up the wrong path with my assumption?

By the way, I am in no hurry to rush out and buy something yet as I would like to get all the good oil to help me make an informed decision on my future purchase. Thanks for any help with my question.

Phil

[Allan_L (Allan)]

Hi Phil,
Welcome to IIS
You are not far from me (I am in Wyong Shire).
Non motorised DOBs generally have a handle/knob near the top end of the scope with which the viewer can manually move the DOB to keep the object in the field of view.
I find it a little difficult sometimes, but thats probably because I don't own a DOB and the view is reversed compared to my SCT.
Owners report no problems as you get used to the required amount of force and direction to keep up with objects.
And yes, in theory it would be more difficult as the magnification increases (field of view decreases). But they seem to manage with ease even high mag planetary viewing.

Since youare so close, and you are on a research mission, why not come along to our monthly viewing sessions, up at Mangrove Mountain. Usually the Saturday(s) close to New Moon. There is generally a Thread in the Star Parties forum advising when and Mike has a Sticky at the toip of that forum with directions and map.
(NOTE: it is also known as and often referred to as "The Pony Club", as that is what the grounds are used for in daylight hours)

We usually have 10 to 20 IIS members there and cover a range of telescope types DOB SCT Newtonians bino-viewers imagers. Some are tracking, some are manual, some are computerised GOTO some are push to. In Dobs we often get Orion Skywatcher GSO Meade Lightbridge and occassional SDM. And they range from 8 inch to 22 inch.

Atmosphere is friendly and informal. You do not need to bring a scope, but all are welcome. Or binos. Bring a comfortable chair.
We are happy to share our views, equipment, and experiences.

Hope to see you there.
Note some of us will be at IISAC this new moon. Weather permitting there will still be others up at Mangrove Mountain who will make you welcome.
Or better still, come along to IISAC, even if just one or two nights.

[astroron (Ron)]

Phil and, Tracking as you put it at high magnification is just a little bit more difficult than at lower power with a Dob, but it is a skill you can only achieve with experience .
As you learn to controll the scope and use higher mag the easier it gets
Jupiter for instance will move quite quickly through a 13mm eyepiece in a 40cm scope with a magnification of x140,smaller objects like faint galaxies hang around a little bit longer.
One of the tricks is to get wide field eyepieces
Cheers

[Filcon (Phillip)]

Thanks so much for taking the time to answer my question, Allan & Ron. Ok it seems I will be able to track manually to start with and that is good. I'm a unsure as to what way I would like to move with the tracking when I do finally automate it. The pros & cons of Goto and Push-to would be worth a little explanation relating to say, a 8" or 10" DOB if someone has the time to enlighten me! I think I can see some myself, but I'm sure those using the systems would be far better able to offer many more worthy points.

Thanks for the invite to the "The Pony Club", Allan...I may just take you up on that offer a little down the track. We do have the coming together of the members of the NAS that meet for viewing, only a few Klm from my home. I no doubt will visit that site too. I think the more you mix with enthusiasts, the more info can be passed on.

Phil

[barx1963 (Malcolm)]

I'll summarise the pros and cons of go-to versus manual in dobs.

Go-To
Pros
- no need to star hop or learn the sky
- usually quick and easy to set up
- maximises time at eypiece
Cons
-$$$$
- you get less aperture for the same dollars and aperture always wins (IMHO)
- you still need to learn a bit of the sky to align
- you need to align once gear is setup
- more things to go wrong
- dependant upon batteries or a power source
- to get best value you will proably still need to use charts or guides to figure out what to point the scope at anyway.

Manual

Pros
- less $$$$ per inch of aperture eg 12" dob is only around $850 - $1000 as against $2000 - $3000 for same in go to.
- Even easier to setup
- no alignment
- no electrical power required unless for dew heaters
- less to go wrong mechanically or electically
- no handset procedures to learn or figure out in the dark

Cons
- you have to get charts
- you have to learn the night sky a bit (but isn't that we are wanting to do anyway?)

As you can tell I am a fan of manual, while go-to has its place and everyone is different, you need to know how they differ for the money and it is usually not a good idea to sacrifice aperture for the sake of go-to.

[Allan_L (Allan)]

Additionally,

Once you locate an object, Go-To usually has tracking, to keep it in the eyepiece.

Push To:
Pros:
Less $$$ than GoTo
Less power requirements
Less to go wrong
40,000 items easy to locate in data base (same as GoTo)
Quiet operation (this is important to some)
"Identify" option available
"Night Tour" option available

Cons
More $$$ than manual

Push to scopes include
Orion Intelliscope
Skywatcher,
as well as
Argo Navis system which can be added to any DOB.

From what I hear, Argo is system of choice, especially since it is Aussie made, but adds approx $1,000 to the cost of a manual DOB. However, it seems to have the better pointing accuracy.