Would this be a good first scope?

[aetherius]

Thanks everyone , this has been a very informative thread for a person like me who is considering the purchase of a telescope.

How long do objects stay in view with an 8-10" dob? I realize the answer depends on the object in question, but for starters, Saturn and Jupiter, and then some 'typical' DSO's.

I had a small scope when I was a kid and recently caught the bug again when my 2nd grader asked for a telescope. I like everything I've read about the dob's (and their price) but I also think I would like the convenience of a motorized tracking system.

Bottom line -Will my kids and neighbors be able to look through a dob for a resonable length of time without having to constantly adjust the scope to keep targets in view?

Thanks!

 

[jsontag]

Thanks everyone , this has been a very informative thread for a person like me who is considering the purchase of a telescope.

How long do objects stay in view with an 8-10" dob? I realize the answer depends on the object in question, but for starters, Saturn and Jupiter, and then some 'typical' DSO's.

I had a small scope when I was a kid and recently caught the bug again when my 2nd grader asked for a telescope. I like everything I've read about the dob's (and their price) but I also think I would like the convenience of a motorized tracking system.

Bottom line -Will my kids and neighbors be able to look through a dob for a resonable length of time without having to constantly adjust the scope to keep targets in view?

Thanks!

That is a great question. I would like to know the answer to that myself.

 

[MeteorWayne]

It depends on the eyepiece, and hence the magnification. At high power (200X or so) it's probably less that a minute. At lower power, a minute or two. I generally take a look in between viewers and nudge it back so that it drifts across the Field of View as each person watches. Once you get the hang of it, it only takes a second or two to tweak the postion.

 

[crazyeddie]

How long do objects stay in view with an 8-10" dob? I realize the answer depends on the object in question, but for starters, Saturn and Jupiter, and then some 'typical' DSO's.

I had a small scope when I was a kid and recently caught the bug again when my 2nd grader asked for a telescope. I like everything I've read about the dob's (and their price) but I also think I would like the convenience of a motorized tracking system.

Bottom line -Will my kids and neighbors be able to look through a dob for a resonable length of time without having to constantly adjust the scope to keep targets in view?

Thanks!

Yep, you have nailed the biggest disadvantage of a dobsonian telescope.....the need to constantly "nudge" it to keep objects in view. For this reason, they are best suited to low-to-medium magnifications.....high power planetary viewing can become a frustrating experience if you do not have butter-smooth bearings on your dobsonian. This can be mitigated somewhat by the use of wide-angle eyepieces, which will keep the object in view longer than a standard design, and thus will require less "nudging" to keep the object centered.

However, there is technology available to solve even this problem. The first is an equatorial platform, sometimes called a poncet platform. It's basically a simple way of giving your dobsonian a clock drive. I won't try to explain how it works, but all you have to do is align the platform with true north, set you dobsonain on the platform, then activate it. It will track any object you point to for up to 75 minutes before needing resetting. They run on batteries, and they range in price from kits you can assemble yourself for less than $300 to beautiful, commercially-made models that start around $900. If you are very handy and like to build things from scratch, there are even websites that show you how to build one yourself, such as this one:

http://members.ziggo.nl/jhm.vangastel/A ... _index.htm

Here are some links to companies that make equatorial platforms:

http://www.roundtableplatforms.com/wst_page4.html

http://www.equatorialplatforms.com/dobs ... forms.html

The other way of enabling dobsonians to track object is with motors that connect to the altitude and azimuth axis of your telescope, such as the one JMI makes especially for the Meade Lightbridge telescope, called "Train N Track". You can view it here:

http://www.jimsmobile.com/buy_acc_light ... ightbridge

There was another company that made similar devices, the Tech 2000 Dob-Driver, but I believe they are no longer in business. In any case, as long as you have money to spend, there are solutions to just about any telescope problem!

 

[aetherius]

Thanks crazyeddie. You have provide the 'nudge' I needed toward a Dob. We can get to know the scope and sky then look into a tracking device if needed.