> http://www.equatorialplatforms.com/
>
> I know they are expensive, but are they really worth it for a variety of
> imaging?  I think for planets, but I think the DSOs is a whole different
> field by itself requiring extreme precision over time.
>
> But, I don't have the experience in this area.

That's the main platform manufacturer.  I've heard good things about them, but
for $2000+ (price of their dual axis models) you could buy an Orion Atlas and
scope which would probably work a lot better.

for me:

Visual observing = biggest dob you can lug around and afford.

Imaging = separate quality GEM

Of course, the old 'while we're at it' applies.  I'm just finishing installing a
9' fiberglass observatory in my back yard.  I'm embarrassed at how much I've
spent in this hobby!   I have a very patient and understanding wife!

John Wunderlin
Mineral Point, WI
XT10i

John,

Thanks for the tips.  I like the "mask" tip.  I was aware of it, but
now, I see the practicality in my situation.  Thank you.

Regarding equatorial platforms, this is the website I've seen advertised
a lot in Sky&Telescope and/or Astronomy:

http://www.equatorialplatforms.com/

I know they are expensive, but are they really worth it for a variety of
imaging?  I think for planets, but I think the DSOs is a whole different
field by itself requiring extreme precision over time.

But, I don't have the experience in this area.

Dan


John wrote:
>
>
>> I have an equatorial mount for my 6" reflector, but I am working on
>> repairs for it and haven't used it in a while.
>
> Also note that not all GEMS are going to be good enough for imaging DSOs
> if you want to eventually go that route. I suggest doing some research
> on cloudynights.com before you make the leap and spend too much money.
>
>> Yes, two huge big problems for me, without an sideral mount, is
>> focusing, and video adjusting. Even if I had someone, is still
>> is big hassle.
>
> Focusing: Bahtinov Mask is a great tool for this. There's a cool website
> where you can print a pattern and make one yourself
> http://astrojargon.net/MaskGen.aspx
> <http://astrojargon.net/MaskGen.aspx> Note that you have to first focus
> on a bright star- the masks don't work directly on planets or the moon.
>
> (disclaimer here: I own spike-a.com which is listed on this website)
>
> Or you can buy a premade one from a few places :)
>
> Video adjusting: This is really trial and error. Set it as manual, and
> try a few gain/exposure settings until you find one that works for
> whichever object you're imaging. I've found Saturn, Jupiter and the Moon
> all require different settings.
>
>> I wondered how some of the new equatorial mounts work on the Dobs? Have
>> you seen or have any experience with those? They are expensive, more
>> deisgned for imaging planets and some DSOs. I've read about it, but
>> don't have any experience with it.
>
> Are you talking about EQ platforms or something else? I own a RoundTable
> EQ platform which unfortunately is no longer made, but there are 1 or 2
> other manufacturers out there.
>
> There are some new dobs coming out with tracking, but AFAIK they are
> alt/az based tracking, not EQ. That would still be fine for planetary &
> lunar imaging, but introduces field rotation on longer exposures.
>
> HTH
>
> John Wunderlin
> Mineral Point, WI
> XT10i
>
>

> > Yes, two huge big problems for me, without an sideral mount, is
> > focusing, and video adjusting.  Even if I had someone, is still
> > is big hassle.
>
> Focusing: Bahtinov Mask is a great tool for this.

Another tip- use Polaris to focus the scope with the mask.  That's the one star
that won't run away from you while trying to set focus :)

John Wunderlin
Mineral Point, WI
XT10i

> I have an equatorial mount for my 6" reflector, but I am working on
> repairs for it and haven't used it in a while.

Also note that not all GEMS are going to be good enough for imaging DSOs if you
want to eventually go that route. I suggest doing some research on
cloudynights.com before you make the leap and spend too much money.

> Yes, two huge big problems for me, without an sideral mount, is
> focusing, and video adjusting.  Even if I had someone, is still
> is big hassle.

Focusing: Bahtinov Mask is a great tool for this.  There's a cool website where
you can print a pattern and make one yourself
http://astrojargon.net/MaskGen.aspx  Note that you have to first focus on a
bright star- the masks don't work directly on planets or the moon.

(disclaimer here: I own spike-a.com which is listed on this website)

Or you can buy a premade one from a few places :)

Video adjusting:  This is really trial and error.  Set it as manual, and try a
few gain/exposure settings until you find one that works for whichever object
you're imaging.  I've found Saturn, Jupiter and the Moon all require different
settings.

> I wondered how some of the new equatorial mounts work on the Dobs?  Have
> you seen or have any experience with those?  They are expensive, more
> deisgned for imaging planets and some DSOs.  I've read about it, but
> don't have any experience with it.

Are you talking about EQ platforms or something else?  I own a RoundTable EQ
platform which unfortunately is no longer made, but there are 1 or 2 other
manufacturers out there.

There are some new dobs coming out with tracking, but AFAIK they are alt/az
based tracking, not EQ.  That would still be fine for planetary & lunar imaging,
but introduces field rotation on longer exposures.

HTH

John Wunderlin
Mineral Point, WI
XT10i

Hi Darrell,

Wow ... what a hard time you had, but glad you made significant
improvements.

I have the Orion SkyQuest XX12i IntelliScope Truss Dobsonian, and do not
have anything you mentioned here.

I've had the XT10 against my 12", and I have noticed a nice difference
between them with my 12" bringing in more detail and little more light.

I use the new Hotech SCA-2" Crosshair collimator for my scope and it
takes about 5 mins to do a accurate alignment, especially, when it's
dark. :-)  I have the Cheshire also, but don't use it much.

Thanks for sharing this unique but interesting adventure you had. You'll
be a better user as a result.

Dan


darrellrspencer wrote:
>
>
> Hi folks! New to this forum, but am very active on numerous others,
> Cloudy Nights, Astromart, etc. Been active (on and off) in astronomy for
> several decades. Obssessed for the last 6 years or so. All my posts
> won't be so lengthy, but I wanted to query the longtime Skyquest 12"
> users on my recent experiences.
>
> I ran into a great opportunity on an Orion 12" Intelliscope last Monday.
> I found the scope essentially unused but missing the altitude encoder. I
> was able to, justifiably, get the seller to come off his already low
> price due to the missing encoder. He'd obviously not used the Computer
> Aid. Anyway, home it went and my beloved and heavily used 10"
> Intelliscope immediately went up for sale (still is).
>
> I realize that a reasonable person would have gone from 10" to 16"ish,
> but if I get my (very fair) price on the 10, it'll be a free upgrade –
> with funds leftover!!
>
> * * *
>
> So, after moving my Feathertouch, Telrad and mirror fan over to the
> XT12, I collimated it down to a gnat's behind. I figured I was ready for
> this weekend's trip to Sentinel (far SW Arizona desert). But with Monday
> night's GRS transit, I thought I'd take the 12 out to throw the best
> resolution I had at it.
>
> That was 1st light.
>
> Imagine my surprise when, even after having the tube equalizing at
> temperature for over an hour, defocused objects were decidedly
> triangular. VERY TRIANGULAR. Even fainter stars had three prominent
> spikes. To me, it looked like a classic pinched mirror condition. So, I
> pulled the tube back inside, yanked the cell and backed way off on the
> three mirror hold-down clamps. I re-collimated and took her back
> outside. The prominent triangles and spikes were gone, but images were
> still smeared over and good focus at mags greater than about 60x were
> almost impossible.
>
> So, at that point it was late, I had work the next morning, I was bummed
> and figured I certainly wouldn't be taking it to Sentinel. And I missed
> the GRS transit.
>
> But, Tuesday night brought better news!
>
> I believe the hulking beast was just horribly out of collimation -
> including the focuser not being square on the tube. (I got reflections
> of the Cheshire barrel I'd never seen that clued me in on that). I spent
> a lot of time tweaking the collimation.
>
> But, that wasn't the real problem. I believe that, not only were the
> primary mirror "hold-down clips" WAAAYY too tight, the primary was also
> "tweaked" hard against the springs almost as far as it would go. I don't
> think that was a good thing, either. (I may need stronger springs). So,
> I suspect that both conditoins had conspired to distort the primary and
> cause severe astigmatism. Whatever the root cause or combination of
> causes, it appears to be very much improved now. I'm sure other folks
> could get collimation closer than me, but at this point, I'm ready to
> say that it'll do, but the mirror is probably not as good as my 10".
>
> Is this something that's been commonly reported with XT12 users? I've
> not followed this forum and a cursory search of the archives didn't
> reveal much.
>
> Thanks in advance, both if you've read this far and if you might have
> any input!
>
> Clear skies and huge, dilated pupils,
>
> Darrell Spencre
>
>

Er...uh...that would be SpencER.

(Glad it's Friday).

--- In skyquest-telescopes@yahoogroups.com, "darrellrspencer" <dspencer@...>
wrote:
* * *
>
> Clear skies and huge, dilated pupils,
>
> Darrell Spencre
>

On Fri, Nov 13, 2009 at 10:56 AM, darrellrspencer <dspencer@...> wrote:
> Is this something that's been commonly reported with XT12 users?

The far east solid tube dobs (Orion, Hardin, etc) have two common
pinch points on the mirrors.
The main one, you found - over tightened primary mirror clips.  I
suppose they do that to avoid mirror damage during transit.  Easily
fixed.
Another common issue is the secondary.  Most of the newer ones slide
into the holder and if the holder pinches the mirror at all, it will
also muck things up.  This is _USUALLY_ fixed by removing the mirror
and lightly sanding the inside of the holder until the mirror slides
in and out without any pinching.  Careful not to get it too lose, else
it won't stay in place.

The other common problem with them is also another one you found - out
of square focuser.  Again, easy to fix, you just need to take the
time.

A really good resource for dialing in these scopes is Barbara and
Robert Thompson's "Astronomy Hacks".  RBT is a member here and can
give feedback if there is something that doesn't make sense.  It has a
lot of good info for other scopes as well, but I found it particularly
useful for tweaking our dobs for best performance.

G'Luck and welcome to the group

<RE>

Hi folks!  New to this forum, but am very active on numerous others, Cloudy
Nights, Astromart, etc.  Been active (on and off) in astronomy for several
decades.  Obssessed for the last 6 years or so.  All my posts won't be so
lengthy, but I wanted to query the longtime Skyquest 12" users on my recent
experiences.

I ran into a great opportunity on an Orion 12" Intelliscope last Monday.  I
found the scope essentially unused but missing the altitude encoder.   I was
able to, justifiably, get the seller to come off his already low price due to
the missing encoder.   He'd obviously not used the Computer Aid.   Anyway, home
it went and my beloved and heavily used 10" Intelliscope immediately went up for
sale (still is).

I realize that a reasonable person would have gone from 10" to 16"ish, but if I
get my (very fair) price on the 10, it'll be a free upgrade – with funds
leftover!!

* * *

So, after moving my Feathertouch, Telrad and mirror fan over to the XT12, I
collimated it down to a gnat's behind.  I figured I was ready for this weekend's
trip to Sentinel (far SW Arizona desert).  But with Monday night's GRS transit,
I thought I'd take the 12 out to throw the best resolution I had at it.

That was 1st light.

Imagine my surprise when, even after having the tube equalizing at temperature
for over an hour, defocused objects were decidedly triangular.  VERY TRIANGULAR.
Even fainter stars had three prominent spikes.  To me, it looked like a classic
pinched mirror condition.  So, I pulled the tube back inside, yanked the cell
and backed way off on the three mirror hold-down clamps.  I re-collimated and
took her back outside.  The prominent triangles and spikes were gone, but images
were still smeared over and good focus at mags greater than about 60x were
almost impossible.

So, at that point it was late, I had work the next morning, I was bummed and
figured I certainly wouldn't be taking it to Sentinel.   And I missed the GRS
transit.

But, Tuesday night brought better news!

I believe the hulking beast was just horribly out of collimation - including the
focuser not being square on the tube.  (I got reflections of the Cheshire barrel
I'd never seen that clued me in on that).   I spent a lot of time tweaking the
collimation.

But, that wasn't the real problem.  I believe that, not only were the primary
mirror "hold-down clips" WAAAYY too tight, the primary was also "tweaked" hard
against the springs almost as far as it would go.  I don't think that was a good
thing, either.  (I may need stronger springs).  So, I suspect that both
conditoins had conspired to distort the primary and cause severe astigmatism. 
Whatever the root cause or combination of causes, it appears to be very much
improved now.  I'm sure other folks could get collimation closer than me, but at
this point, I'm ready to say that it'll do, but the mirror is probably not as
good as my 10".

Is this something that's been commonly reported with XT12 users?  I've not
followed this forum and a cursory search of the archives didn't reveal much.

Thanks in advance, both if you've read this far and if you might have any input!

Clear skies and huge, dilated pupils,

Darrell Spencre

Thanks John.

I appreciate your comments.  I've heard a lot of good things about the
GEM mounts also.

I have an equatorial mount for my 6" reflector, but I am working on
repairs for it and haven't used it in a while.  I intend to try some
ideas out on that platform later on.

Yes, two huge big problems for me, without an sideral mount, is
focusing, and video adjusting.  Even if I had someone, is still is a big
hassle.

I wondered how some of the new equatorial mounts work on the Dobs?  Have
you seen or have any experience with those?  They are expensive, more
deisgned for imaging planets and some DSOs.  I've read about it, but
don't have any experience with it.

Dan



John wrote:
>
>
>
>> Not sure if I will spend any more money on this project, but without
> celestial drive, it is frustrating, but it can work and, the light
> output is very sufficient to drive the webcam. I thought someone
> mentioned about cmos vs ccd. To me, it doesn't make much difference.
>
> I love astrophotography. I think it's really cool being able to record
> celestial objects. Using a Dob for imaging can be fun as a novelty, but
> if you want to go down that path be ready for a never ending list of
> equipment to upgrade.
>
> You're correct about the video setting- you must set it manually to get
> good results. The auto adjust isn't used to working with planets. It
> works ok on the moon, but even there you'll get better results adjusting
> the settings manually.
>
> I bought an EQ platform partially to start doing some astrophotography.
> Knowing what I know now, I wouldn't go that route. I like my EQ
> platform, but I only use it for visual work and public presentations.
>
> Nothing beats a good GEM mount for imaging.
>
> John Wunderlin
> Mineral Point, WI
> XT10i
>
>

> Not sure if I will spend any more money on this project, but without celestial
drive, it is frustrating, but it can work and, the light output is very
sufficient to drive the webcam.  I thought someone mentioned about cmos vs ccd. 
To me, it doesn't make much difference.

I love astrophotography.  I think it's really cool being able to record
celestial objects.  Using a Dob for imaging can be fun as a novelty, but if you
want to go down that path be ready for a never ending list of equipment to
upgrade.

You're correct about the video setting- you must set it manually to get good
results.  The auto adjust isn't used to working with planets.  It works ok on
the moon, but even there you'll get better results adjusting the settings
manually.

I bought an EQ platform partially to start doing some astrophotography.  Knowing
what I know now, I wouldn't go that route.  I like my EQ platform, but I only
use it for visual work and public presentations.

Nothing beats a good GEM mount for imaging.

John Wunderlin
Mineral Point, WI
XT10i

Thanks for the information thats just what I wanted to hear. Ordered the xt10i
last week, its still not arrived so I think I will have to chase it up tomorrow.
I have a 19mm Panoptic which is great lowpower eyepiece in my 5 inch dob but I
wanted a bit more magnification for the Orion and the 12t4 gets some great
reviews and a decent scope deserves a decent eyepiece (or three) IMHO.

Thanks again,

Chris.

> I'm  thinking of getting a nice new eyepiece to go with my
> new scope (the xt10i, when it arrives) and I'm thinking of
> getting a Nagler 12T4 but I have read that they don't come
> to focus in the XT10i. Is this correct and if so how could
> I get over this problem?

The 12mm Type 4 Nagler is easily my favorite eyepiece in my
XT10 and it reaches focus easily near mid travel. *Note*
that this is a 1-1/4" eyepiece and I am using it in a 2" -
1-1/4" adapter. If you drop the 2" skirt into your focuser
without the adapter the eyepiece will sit nearly 2" lower
and then won't hit focus.

You could also use an extension tube but I have no security
issues treating it as a 1-1/4" eyepiece. I wish that TeleVue
had just left off the 2" skirt or had positioned it so as it
would be par focal with theie other 2" eyepieces.

You will love the 12mm Type 4 Nagler (until you look through
a 13mm Ethos!).

Welcome to the group and clear skies,

Phil Lefever
Burnsville, MN
Original XT10

Outstanding EP for the X10! And the used prices have been dropping on
Astromart.com with TV Ethos  coming out. I never had a problem with mine and
there's always the TV extension too if it is a problem.

Bob



________________________________
From: chrishoyland33 <chrishoyland@...>
To: skyquest-telescopes@yahoogroups.com
Sent: Wed, November 11, 2009 11:52:34 AM
Subject: [skyquest-telescopes] XT10i & Nagler 12mm Type 4


I'm  thinking of getting a nice new eyepiece to go with my new scope (the xt10i,
when it arrives) and I'm thinking of getting a Nagler 12T4 but I have read that
they don't come to focus in the XT10i. Is this correct and if so how could I get
over this problem?

Thanks.







[Non-text portions of this message have been removed]

I'm  thinking of getting a nice new eyepiece to go with my new scope (the xt10i,
when it arrives) and I'm thinking of getting a Nagler 12T4 but I have read that
they don't come to focus in the XT10i. Is this correct and if so how could I get
over this problem?

Thanks.

Hi Gene,

The seeing wasn't that great; altitude, I am guessing around 28 degrees
or so.  Not very high.

In my case, light wasn't a problem at all; metering has to be manually
adjusted before any serious video to be done, I am guessing.

Hopefully, if the weather cooperates, I'll try Mars in the near future.
  Mars will be higher in altitude.

The biggest problem is focusing.  Jupiter went so fast, it was very hard
to fine focus while watching my laptop, and trying to make fine adjustments.

All in all, it was interesting, but without a sideral drive, it's going
to be iffy.

Dan


g2baraff wrote:
>
>
>
>
> --- In skyquest-telescopes@yahoogroups.com
> <mailto:skyquest-telescopes%40yahoogroups.com>, "dg_frezza" <dan@...> wrote:
>>
>> FYI,
>>
>> Last week, I did an experiment with an old webcam, 1 1/4" adapter, and
> a 2x barlow with my 12" Dob.
>>
>> Here's a short recording showing jupiter coming into view, rather
> quickly, and you can see the webcam's metering trying to adapt at
> Jupiter's very bright image. It was taken 15 frames/per second, 320x240.
> Nothing spectacular, but a few things were clear:
>>
>> 1) Field of view is very small with the barlow
>> 2) Object moves very quickly!
>>
>> Here's the short video in microsoft's wmv format:
>>
>> http://www.frezza.org/jup_barlow.wmv
> <http://www.frezza.org/jup_barlow.wmv>
>>
>> *****************
> Wow! The metering kicks in and you get bands. What altitude was Jupiter
> when you took the shot? Looks like lots of atmospheric refraction (here
> we go again) giving you extra color.
>
> Gene
>
>

--- In skyquest-telescopes@yahoogroups.com, "dg_frezza" <dan@...> wrote:
>
> FYI,
>
> Last week, I did an experiment with an old webcam, 1 1/4" adapter, and a 2x
barlow with my 12" Dob.
>
> Here's a short recording showing jupiter coming into view, rather quickly, and
you can see the webcam's metering trying to adapt at Jupiter's very bright
image.  It was taken 15 frames/per second, 320x240.  Nothing spectacular, but a
few things were clear:
>
> 1) Field of view is very small with the barlow
> 2) Object moves very quickly!
>
> Here's the short video in microsoft's wmv format:
>
> http://www.frezza.org/jup_barlow.wmv
>
>                 *****************
Wow!  The metering kicks in and you get bands.   What altitude was Jupiter when
you took the shot?  Looks like lots of atmospheric refraction (here we go again)
giving you extra color.

Gene

FYI,

Last week, I did an experiment with an old webcam, 1 1/4" adapter, and a 2x
barlow with my 12" Dob.

Not sure if I will spend any more money on this project, but without celestial
drive, it is frustrating, but it can work and, the light output is very
sufficient to drive the webcam.  I thought someone mentioned about cmos vs ccd. 
To me, it doesn't make much difference.

Here's a short recording showing jupiter coming into view, rather quickly, and
you can see the webcam's metering trying to adapt at Jupiter's very bright
image.  It was taken 15 frames/per second, 320x240.  Nothing spectacular, but a
few things were clear:

1) Field of view is very small with the barlow
2) Object moves very quickly!

Here's the short video in microsoft's wmv format:

http://www.frezza.org/jup_barlow.wmv

Your criticisms are very welcomed!

Dan

Hi Gene,

It's interesting to hear the comments concerning this problem, but I
feel there is some basic explanation that hasn't been uncovered or
overlooked that gave rise to his problem.

For what the Intelliscope Object Locator can do, for the money, and the
fact other stars can be used for alignment with no problem, I can't
complain.

Maybe one night, I'll take out my laptop with ECUPRO5, and run the
alignment with that program, and see for myself, how much alignment
error in decimal degrees, it gives.  It's another approach.

During the summer I spent a lot of time facing the North East and doing
more of my astronomy.  The weirdest things I've seen I wouldn't say on
this list, but one night trying to bag a fuzzie in that location, I was
bothered a great deal by ducks flying around my location for a half-hour
and wouldn't shut up!  Keeping my 12" scope level for while to avoid any
poop bombs was terribly frustrating, especially, when the night was a
real good night for viewing!

It's hard to concentrate with all the yakking going on! :-)

Clear skies!

Dan


g2baraff wrote:
>
>
>
>
> --- In skyquest-telescopes@yahoogroups.com
> <mailto:skyquest-telescopes%40yahoogroups.com>, "JohnA" <also_nc@...> wrote:
>>
>> It's Fall already, Gene ;) Summer done slipped away. At 7:30 PM Vega
> is long past culmination, about 45 degrees above the WNW horizon.
>>
>> Steve and Dan both mentioned good warps using Vega and Polaris.
> Polaris is the one alignment star I have never used. It is blocked by my
> roof from the spot I set up in my backyard. Because Vega and Polaris are
> only 51 degrees apart I doubt that I would have tried that combo anyway,
> since the COL's manual recommends a minimum of 60 degrees separation for
> alignment stars.
>>
>> ****************
>>
> O.K. I'm all out of suggestions. Maybe somebody like Dan or Steve or one
> of the other good guys will come up with something that makes more sense
> that I can.
>
> gene
>
>

--- In skyquest-telescopes@yahoogroups.com, "JohnA" <also_nc@...> wrote:
>
> It's Fall already, Gene ;)  Summer done slipped away.  At 7:30 PM Vega is long
past culmination, about 45 degrees above the WNW horizon.
>
> Steve and Dan both mentioned good warps using Vega and Polaris.  Polaris is
the one alignment star I have never used.  It is blocked by my roof from the
spot I set up in my backyard.  Because Vega and Polaris are only 51 degrees
apart I doubt that I would have tried that combo anyway, since the COL's manual
recommends a minimum of 60 degrees separation for alignment stars.
>
>                ****************
>
O.K.   I'm all out of suggestions.  Maybe somebody like Dan or Steve or one of
the other good guys will come up with something that makes more sense that I
can.

gene

--- "g2baraff" <g2baraff@...> wrote:
>
> The ONLY place that is a problem for an Alt Az mount is the zenith.  I should
have (but now you can) check on how close Vega was to the zenith when you
aligned on it.
>
> Gene
>



It's Fall already, Gene ;)  Summer done slipped away.  At 7:30 PM Vega is long
past culmination, about 45 degrees above the WNW horizon.

Steve and Dan both mentioned good warps using Vega and Polaris.  Polaris is the
one alignment star I have never used.  It is blocked by my roof from the spot I
set up in my backyard.  Because Vega and Polaris are only 51 degrees apart I
doubt that I would have tried that combo anyway, since the COL's manual
recommends a minimum of 60 degrees separation for alignment stars.

John Alsobrook
North Carolina

Hi Gene,

I know about these and other equations, but, I don't know what the
Intelliscope uses.  So, trying to plug info into these and other
equations, doesn't answer what exactly Intelliscope uses for equations.
  I thought it might be helpful in the long run in special cases.

Thanks anyways,

Dan


g2baraff wrote:
>
>
>
>
> --- In skyquest-telescopes@yahoogroups.com
> <mailto:skyquest-telescopes%40yahoogroups.com>, Dan <dan@...> wrote:
>>
>>
>> I've tried to find the mathematics that the "Intelliscope" uses, but
>> don't seem to have any luck.
>>
>> ************************
>>
> Try this:
>
> http://www.asahi-net.or.jp/~zs3t-tk/aim/aim.htm
> <http://www.asahi-net.or.jp/~zs3t-tk/aim/aim.htm>
>
> These are basic equations for doing the change from the one coordinate
> system (the one attached to your Dob) to the second coordinate system
> (the one attached to the fixed stars) using your alignment sightings as
> input data to determine the parameters of the transformation. If the
> Intelli code differs from this, I'd (rather confidently - but not 100%)
> guess that the difference is only with regard to changing the analog
> Intelli signal to the digital signal Taki (the author) had in mind. The
> Intelli analog system had not been invented when Taki put dowen his
> ewquations, nor when I wrote mine.
>
> In some cases (this case, for me) it is easier to workout your own
> equations than to try to figure out what someone else has done.
>
> Hope this helps.
>
> Gene
>
>

Same here, John.

Dan


Steve Strange wrote:
>
>
> Anyway, it is more of a curiosity than a concern. There are always
> several other alignment stars available, so not being able to use Vega
> is no problem. Still, I'd like to know if anybody else does get good
> numbers using Vega as one of the alignment stars.
>
> ----------------------------------------------------------
>
> John,
>
> I used Vega and Polaris for a star alignment Saturday night with a warp
> factor of "0".
> At first I did not believe the "0" reading but the locator found each
> object very well.
>
> [Non-text portions of this message have been removed]
>
>

> I noticed that the altitude cable jack on my 10 inch Intelliscope has slight
play- but it is not loose. Will this affect the accuracy of the COL?

The phone jack connectors are designed to have a little give in them.  If you
want to be sure it's working properly, use the hidden functions to test the
encoders (see the manual for instructions).

John Wunderlin
Mineral Point, WI
XT10i

Anyway, it is more of a curiosity than a concern. There are always several other
alignment stars available, so not being able to use Vega is no problem. Still,
I'd like to know if anybody else does get good numbers using Vega as one of the
alignment stars.

--------------------------------------------------------------------------------\
--------------------------------------------------------------

John,

I used Vega and Polaris for a star alignment Saturday night with a warp factor
of "0".
At first I did not believe the "0" reading but the locator found each object
very well.




[Non-text portions of this message have been removed]

--- In skyquest-telescopes@yahoogroups.com, "JohnA" <also_nc@...> wrote:
>>
> To clarify, I really don't think Fomalhaut is the cause, but rather, Vega.
>
>               *********************
>
Dan mentioned places in the sky tha you should keep away from for alignement
puposes.

The ONLY place that is a problem for an Alt Az mount is the zenith.  I should
have (but now you can) check on how close Vega was to the zenith when you
aligned on it.

Gene

--- In skyquest-telescopes@yahoogroups.com, Dan <dan@...> wrote:
>
>
> I've tried to find the mathematics that the "Intelliscope" uses, but
> don't seem to have any luck.
>
>              ************************
>
Try this:

      http://www.asahi-net.or.jp/~zs3t-tk/aim/aim.htm

These are basic equations for doing the change from the one coordinate system
(the one attached to your Dob) to the second coordinate system (the one attached
to the fixed stars) using your alignment sightings as input data to determine
the parameters of the transformation.   If the Intelli code differs from this,
I'd (rather confidently - but not 100%) guess that the difference is only with
regard to changing the analog Intelli signal to the digital signal Taki (the
author) had in mind.  The Intelli analog system had not been invented when Taki
put dowen his ewquations, nor when I wrote mine.

In some cases (this case, for me) it is easier to workout your own equations
than to try to figure out what someone else has done.

Hope this helps.

Gene

John,

I just checked my Intelliscope Object Locator for the software version,
and it gives v1.49.

I purchased my 12" Truss Dobsonian with the locator earlier this year.

I am wondering if it is indeed the same software version others are using.

Dan


JohnA wrote:
>
>
>
>
> --- "g2baraff" <g2baraff@...> wrote:
>>
>>
>> So John's problem is still an open (and an interesting) one.
>>
>> Gene
>>
>
> To clarify, I really don't think Fomalhaut is the cause, but rather,
> Vega. I'm at 35.07 deg latitude, so Sunday night at 7:30 PM, for
> example, when I last tried Fomalhaut and Vega, Fomalhaut was 24 degrees
> above the horizon. That eliminates refraction error. Also, after trying
> Vega & Fomalhaut, I aligned using Fomalhaut and Deneb and got 0.1 warp.
> Fomalhaut and Deneb are separated by 81 degrees, not grossly different
> from the 91 degrees between Fomalhaut and Vega (unless the 91 degrees
> actually is too far apart, which is something I hadn't considered until
> reading a previous comment).
>
> Maybe it is a firmware hiccup. My COL is a first generation 1994 model.
> Orion has never offered a firmware upgrade and I doubt that the first
> generation was perfect.
>
> Anyway, it is more of a curiosity than a concern. There are always
> several other alignment stars available, so not being able to use Vega
> is no problem. Still, I'd like to know if anybody else does get good
> numbers using Vega as one of the alignment stars.
>
> John Alsobrook
> North Carolina
>
>

--- "JohnA" <also_nc@...> wrote:
>
> My COL is a first generation 1994 model.


Old, but not that old!  Make that a 2004 model.

John Alsobrook
North Carolina

--- "g2baraff" <g2baraff@...> wrote:
>
>
> So John's problem is still an open (and an interesting) one.
>
> Gene
>


To clarify, I really don't think Fomalhaut is the cause, but rather, Vega.  I'm
at 35.07 deg latitude, so Sunday night at 7:30 PM, for example, when I last
tried Fomalhaut and Vega, Fomalhaut was 24 degrees above the horizon.  That
eliminates refraction error.  Also, after trying Vega & Fomalhaut, I aligned
using Fomalhaut and Deneb and got 0.1 warp.  Fomalhaut and Deneb are separated
by 81 degrees, not grossly different from the 91 degrees between Fomalhaut and
Vega (unless the 91 degrees actually is too far apart, which is something I
hadn't considered until reading a previous comment).

Maybe it is a firmware hiccup.  My COL is a first generation 1994 model.  Orion
has never offered a firmware upgrade and I doubt that the first generation was
perfect.

Anyway, it is more of a curiosity than a concern. There are always several other
alignment stars available, so not being able to use Vega is no problem.  Still,
I'd like to know if anybody else does get good numbers using Vega as one of the
alignment stars.

John Alsobrook
North Carolina

--- In skyquest-telescopes@yahoogroups.com, Dan <dan@...> wrote
>
> BTW, I checked the Intelliscope's manual, page 25, and #10 near the
> bottom of the page, it talks about refraction.  However their
> reference for stars "near the horizon can appear as much as 2
> degrees away from the their actual postion."  Not sure if this
> corresponds to 0.57 degrees raise for an object on the horizon.
>
>                   **********************
>
No.  It doesn't.  I'll check my numbers again. (I sometimes do that after a
couple of glasses of wine with dinner -- posting I mean without double
checking.)  If the Intelli manual is right, then  explanation IS the most
likely.
>
>                ******************************
>
> I've tried to find the mathematics that the "Intelliscope" uses, but
> don't seem to have any luck.  Other sources tell us that stars on
> the celestial equator and stars which has +/- of their declination
> should be avoided since it may bring instability into the system
> when using two star alignment with certain sets of equations.
>
>          **********************
>
That's not true for an alt-az mount like a dob.  Celestial equator and celestial
pole are not special directions for a mount whose main axis is vertical.   The
story MAY be different for a polar aligned scope.  I'll check out the math
tomorrow when I'm fully alert.  Therer ARE some combinations that can give you a
zero or very small warp factor and still give you lousy pointing.  I've posted
to our files about it.  But THAT is not at all what John has brought up here.
>
>                   *****************
>
> Also, the manual suggest checking one's vertical stop with a
> carpenter's level to be sure nothing unusual is going on as the
> scope rotates on its base.  I am a little concerned through time,
> that wood will warp a little here and there, and might produce some
> spurious results in one area and not the other.
>
>                    *********************
>
That (covert mechanical subtleties) is another fruitful area.   Good going!

Gene