computerized dobs- how accurate?

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Date: 23 Sep 2006 11:13:49
From: Jason Able
Subject: computerized dobs- how accurate?

In this age of instant gratification, especially where youth are concerned,
I have begun the search for a telescope that will allow as fast a finding of
DSO and other objects as quickly as possible. I am a fairly new school
teacher and we have an older Meade 8" Dob at school. Last year, I tried to
use the Dob to find DSO's, but it took too long to star hop and the kids
became impatient, which started leading to discipline problems. I see that
Orion offers a dob with a computer that is supposed to slew? to objects once
they're punched in to the computer. How well does a scope like this work
and can it quickly and accurately place a DSO in the eyepiece? Several
reviews I've read suggest alignment problems. The bottom line is that I
would either like to purchase a new dob, able to accurately find a given
object quickly, or adapt our existing dob to perform the same task.

Suggestions would be appreciated.

Thanks,
Jason Able

Date: 23 Sep 2006 07:42:11
From: Joe S.
Subject: Re: computerized dobs- how accurate?

"Jason Able" <jazastr@erls.net > wrote in message
news:NF8Rg.11267$v%4.7241@newsread1.news.pas.earthlink.net...
> In this age of instant gratification, especially where youth are
> concerned,
> I have begun the search for a telescope that will allow as fast a finding
> of
> DSO and other objects as quickly as possible. I am a fairly new school
> teacher and we have an older Meade 8" Dob at school. Last year, I tried
> to
> use the Dob to find DSO's, but it took too long to star hop and the kids
> became impatient, which started leading to discipline problems. I see
> that
> Orion offers a dob with a computer that is supposed to slew? to objects
> once
> they're punched in to the computer. How well does a scope like this work
> and can it quickly and accurately place a DSO in the eyepiece? Several
> reviews I've read suggest alignment problems. The bottom line is that I
> would either like to purchase a new dob, able to accurately find a given
> object quickly, or adapt our existing dob to perform the same task.
>
> Suggestions would be appreciated.
>
> Thanks,
> Jason Able
>
>

You seem to be referring to the Orion Intelliscope Dobs. I own an XT-12
Intelliscope and am quite pleased with the ability of the system to locate
objects. Remember, though, some DSO's are truly faint and fuzzy -- your
scope can be pointed directly at the DSO and you won't see a thing because
of light pollution or other viewing conditions.

Here is a link to my home page article about the XT-12; the Orion Dobs are
all similar except for the mirror size:
http://www.schlatter.org/Dad/Astronomy/XT%2012.htm

Here is a link to my home page article about the Intelliscope:
http://www.schlatter.org/Dad/Astronomy/intelliscope%20page.htm

As with any computerized system, setup is critical. When you assemble the
scope, you must follow carefully the instructions about making certain the
tube stands vertical in relation to the base. Then, when you align the
scope -- which you do with each observing session -- you must pick two
alignment stars that are at least 60 degrees apart and you must center each
star in the field of view -- which means an eyepiece with crosshairs is
advisable, though not required.

There is a learning curve with the Intelliscope but it's not at all
difficult. The Intelliscope controller is easy to use but you do have to
follow the steps in using it and if you use it only occasionally as I do,
you have to re-learn it every time you pull it out.

You could put together some interesting lessons involving the students in
assembling the scope, setting up the Intelliscope system, and aligning the
scope at the start of each observing session.

Also -- you do not have to use the Intelliscope system -- if you are viewing
the moon, planets, or other easy to find objects, just leave the
Intelliscope controller in the box. If you want to use the Intelliscope
later in an observing session, just stand the scope vertical, plug in the
controller, and align it.

Date: 23 Sep 2006 19:14:13
From: Bob May
Subject: Re: computerized dobs- how accurate?

If you're going to a computerized dob, even the point indicators like the
Sky Commander will help. If you do a good setup, the item will be in the
EP, usually near the center when the device is indicating that you're on.
I'd also tend to keep with a few objects that are relatively easy to find
and are somewhat bright. Leave the faint fuzzies to when you have exclusive
or near exclusive access to the scope as the kids often don't know what they
are looking at.

--
Yeppie, Bush is such an idiot that He usually outwits
everybody else. How dumb!

Date: 23 Sep 2006 10:56:19
From: Don't Be Evil
Subject: Re: computerized dobs- how accurate?

Jason Able wrote:
> In this age of instant gratification, especially where youth are concerned,
> I have begun the search for a telescope that will allow as fast a finding of
> DSO and other objects as quickly as possible. I am a fairly new school
> teacher and we have an older Meade 8" Dob at school. Last year, I tried to
> use the Dob to find DSO's, but it took too long to star hop and the kids
> became impatient, which started leading to discipline problems. I see that
> Orion offers a dob with a computer that is supposed to slew? to objects once
> they're punched in to the computer. How well does a scope like this work
> and can it quickly and accurately place a DSO in the eyepiece? Several
> reviews I've read suggest alignment problems. The bottom line is that I
> would either like to purchase a new dob, able to accurately find a given
> object quickly, or adapt our existing dob to perform the same task.
>
> Suggestions would be appreciated.
>
> Thanks,
> Jason Able

I have one and love it. It seems to depend on how exactly you center
the stars during setup. I use a 5mm eyepiece for that purpose. The
result is that objects are always in the center 2/3rds with the 5mm and
dead center with lower powers. You could probably get it better using a
reticle eyepiece.

It does depend on carefully checking the vertical alignment when
assembling the scope. And, it's much less accurate on soft ground.

It does not slew. Rather, it guides you manually aiming it. This
works very well, and only takes about 20 seconds, but it does mean
that it doesn't track objects as the earth rotates. Nonissue for
low-power deep sky observing, but a little hassle with planets and
other high-power targets. Nevertheless, it moves so smoothly that I
can easily track planets at 480x, the theoretical limit of an 8".

You might really prefer a scope that tracks when you have a line of
schoolkids waiting. I usually have to re-aim between each viewer if
I'm using high powers. Options would include an EQ platform for your
existing dob, a small newtonian reflector on an EQ or computerized
alt-az mount (large ones are too tall for kids to see into without a
ladder), an SCT or an MCT. What's your budget?

Greg

Date: 24 Sep 2006 16:18:10
From: Willie R. Meghar
Subject: Re: computerized dobs- how accurate?

"Jason Able" <jazastr@erls.net > wrote:

>The bottom line is that I
>would either like to purchase a new dob, able to accurately find a given
>object quickly, or adapt our existing dob to perform the same task.

Some other possibilities (besides updating your telescope or getting a
new one) that *might* be possible include:

1) Contacting an amateur astronomer in your area who has his/her own
computerized telescope available for student use.

2) Contacting an amateur astronomer in your area who has the
knowledge and capability of quickly pointing a non-computerized
telescope (his/her own, or the school's).

3) Spend some of your own evenings alone with the dob in an effort to
become proficient in pointing it at some of the best celestial sights
-- prior to an outing with students.

Regardless of who's making the decision as to which targets to
observe, that person should have recently observed those targets
themselves in an effort to determine the suitability of each target
for student viewing. They should also have determined in advance
which eyepiece(s) will be used for each target

You might want to have at least one additional teacher or adult on
hand to help keep those students who aren't at the eyepiece at least
somewhat occupied (with perhaps constellation, star, and/or planet
identification; or a discussion session pertaining to anything, such
as the object the telescope is currently pointed at, related to
astronomy).

Willie R. Meghar
http://meghar.blogspot.com/

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Date: 26 Sep 2006 01:05:11
From: John Carruthers
Subject: Re: computerized dobs- how accurate?

Date: 26 Sep 2006 15:06:05
From: canopus56
Subject: Re: computerized dobs- how accurate?