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Date: 17 Jul 2007 23:54:06
From: Jonathan Tomshine
Subject: Mounts: EM-200 vs. G-11
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I've been shopping for a portable equatorial mount with go-to that is also
stable enough & has low enough periodic error for astrophotography --
something sturdy enough to hold a 100-130 mm refractor or a 10" SCT or
Mak.
Like so many people, I was drawn towards the Losmandy G-11, but I've
also been considering the (much more expensive) Takahashi EM-200. I'm
curious if anyone around here has used both mounts and knows what, if
anything, the extra cost of the Takahashi buys?
If anyone has insight into this, or any other recommendations beyond the
G-11 or EM-200, please post a reply. I'll greatly appreciate it, as this
will be a significant investment for me.
Thanks,
Jon
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Date: 18 Jul 2007 06:52:50
From: Davoud
Subject: Re: Mounts: EM-200 vs. G-11
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Jonathan Tomshine wrote:
> I've been shopping for a portable equatorial mount with go-to that is also
> stable enough & has low enough periodic error for astrophotography --
> something sturdy enough to hold a 100-130 mm refractor or a 10" SCT or
> Mak.
>
> Like so many people, I was drawn towards the Losmandy G-11, but I've
> also been considering the (much more expensive) Takahashi EM-200. I'm
> curious if anyone around here has used both mounts and knows what, if
> anything, the extra cost of the Takahashi buys?
>
> If anyone has insight into this, or any other recommendations beyond the
> G-11 or EM-200, please post a reply. I'll greatly appreciate it, as this
> will be a significant investment for me.
Both are very good mounts. I have used a friend's EM-200 only briefly,
but long enough to be impressed. I own a G-11 (and a G-8), however, and
that's where my experience is. I can tell you that for the load you
mention it doesn't make sense to spend the extra money on the EM-200.
The G-11 has a rated capacity of 27 kg/60 lbs (vs. 32 kg/70 lbs for the
Tak if my memory serves me well) and the G-11 capable of handling every
bit of that.
A G-11 bonus that is often overlooked is the simple construction and
modular design; in the event of damage or other failure, the user can
replace any piece of the mount without much grief.
It pays to think ahead, of course. If you expect to have a 150 lb.
instrument load within the next year or so, then neither of these is
for you.
If you buy the Gemini, spring for the Gemini GoTo system. It is an
excellent goto system, is compatible with every known software package
for Mac and Windoze, and takes standard SBIG autoguider output . The
G-11/Gemini will produce needle-sharp stars with an autoguider (and
with careful manual guiding, for that matter.) I think that, as a
practical matter, the G-11/Gemini is the performance equal of just
about any other mount when used within 10-15 lbs of its rated load
(i.e., not over 75 lbs, and then with an 18V power supply.)
Davoud
--
usenet *at* davidillig dawt com
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Date: 18 Jul 2007 00:44:05
From: William R. Mattil
Subject: Re: Mounts: EM-200 vs. G-11
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Jonathan Tomshine wrote:
> I've been shopping for a portable equatorial mount with go-to that is also
> stable enough & has low enough periodic error for astrophotography --
> something sturdy enough to hold a 100-130 mm refractor or a 10" SCT or
> Mak.
Jonathan,
In my opinion a 10 inch SCT would be too much weight and focal length
for real consistent results with the G-11. Which is not to say that it
cannot be done. But it's not a turn key affair. It would help
considerably if the G-11 was in an observatory and out of the wind. But
in a portable situation this is harder to do. FWIW I had a C-11, Van
Slyke Focuser, ST series Camera and a guidescope and ST-4 guide head in
my observatory. Sometimes it worked great. Other times the guiding was
less than what I wanted. But to be perfectly fair this was a *lot* of
payload. At the price that I had invested in the setup I was happy.
>
> Like so many people, I was drawn towards the Losmandy G-11, but I've
> also been considering the (much more expensive) Takahashi EM-200. I'm
> curious if anyone around here has used both mounts and knows what, if
> anything, the extra cost of the Takahashi buys?
The Takahashi has, IMO, better (lower) periodic error and they are much
less trouble to fiddle with. Yes, this comes at a price. You can decide
if it's worth the extra cost. No one else can. One thing that may
influence your decision might be that the EM200 has no PEC. It could
certainly be argued that they don't need it <g > But if you are planning
to use Pempro or other software to tune the tracking or help with polar
alignment they won't work with the EM200.
On the plus side though the Goto on the EM200 I found to be better than
a Gemini. But I will admit that I was rather disappointed in the Gemini.
The mount (G-11) *can* be made to work quite well. But since you didn't
mention anything about a GoTo version .......
>
> If anyone has insight into this, or any other recommendations beyond the
> G-11 or EM-200, please post a reply. I'll greatly appreciate it, as this
> will be a significant investment for me.
Take a look at the AP900 Mount or the newer one that they have out. I
can't recall what the street price is on the EM200. But I do know that
the AP900 is relative easy to get now that AP has upped their production
capacity.
Either way I suspect you'll be pleased with any of these mounts. But if
photography is in your future then I would opt for the EM200 or an AP900.
Regards
Bill
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Date: 18 Jul 2007 06:55:40
From: Davoud
Subject: Re: Mounts: EM-200 vs. G-11
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William R. Mattil wrote:
> In my opinion a 10 inch SCT would be too much weight and focal length
> for real consistent results with the G-11.
?? The G-11 can handle every ounce of it's 60-lb rated capacity, and
then some.
> Which is not to say that it
> cannot be done. But it's not a turn key affair. It would help
> considerably if the G-11 was in an observatory and out of the wind. But
> in a portable situation this is harder to do.
My G-11/Gemini was turn-key. Bought it, installed it in my observatory,
did a drift alignment, and was off and running. That has been the
experience of every Losmandy mount owner I know. And isn't /every/
equatorial mount easier to use in a permanent installation than on a
portable tripod that is put away after each use?
> FWIW I had a C-11, Van
> Slyke Focuser, ST series Camera and a guidescope and ST-4 guide head in
> my observatory. Sometimes it worked great. Other times the guiding was
> less than what I wanted.
Then it doesn't sound like a mount issue.
> But to be perfectly fair this was a *lot* of
> payload. At the price that I had invested in the setup I was happy.
That was on a G-11?
> The Takahashi has, IMO, better (lower) periodic error and they are much
> less trouble to fiddle with.
I've used the Tak mount only briefly, but I was impressed. How long
have you owned EM-200? How much weight is it carrying? Would you buy it
again?
> Take a look at the AP900 Mount or the newer one that they have out...
The OP says that a mount costing about $4k will be "a significant
investment" for him, and you're recommending a mount that costs $8,000?
Davoud
--
usenet *at* davidillig dawt com
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Date: 19 Jul 2007 00:02:31
From: William R. Mattil
Subject: Re: Mounts: EM-200 vs. G-11
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Davoud wrote:
> William R. Mattil wrote:
>
>> In my opinion a 10 inch SCT would be too much weight and focal length
>> for real consistent results with the G-11.
>
> ?? The G-11 can handle every ounce of it's 60-lb rated capacity, and
> then some.
David,
There is no greater fan of a Losmandy mount than I. But I can assure you
that with even just a bare SCT and no goodies (say 35 pounds) wind can
be a *huge* issue. You might recall that the original poster said
"portable" which to me means "not in an observatory" And with that
restriction my statement still stands.
>
>> Which is not to say that it
>> cannot be done. But it's not a turn key affair. It would help
>> considerably if the G-11 was in an observatory and out of the wind. But
>> in a portable situation this is harder to do.
>
> My G-11/Gemini was turn-key. Bought it, installed it in my observatory,
> did a drift alignment, and was off and running. That has been the
> experience of every Losmandy mount owner I know.
Then you obviously do not subscribe to the Losmandy List. There have
been some users that were less than thrilled with the performance out of
the box. If the poster doesn't want to fiddle then this might not be a
great choice for him.
>
>> FWIW I had a C-11, Van
>> Slyke Focuser, ST series Camera and a guidescope and ST-4 guide head in
>> my observatory. Sometimes it worked great. Other times the guiding was
>> less than what I wanted.
>
> Then it doesn't sound like a mount issue.
In my *years* of experience with this I can assure you that it was a
mount problem. Having to readjust the Dec mesh twice a year, while not a
big deal could exasperate someone not expecting it.
>
>> But to be perfectly fair this was a *lot* of
>> payload. At the price that I had invested in the setup I was happy.
>
> That was on a G-11?
I said it was didn't I ?
http://www.celestial-images.com/C-11-1.html
http://www.celestial-images.com/C-11-2.html
http://www.celestial-images.com/M57-LHaRGB-300-5.html
I doubt that you can find someone that has had more crap riding on a
Losmandy mount than I did. From 45 pounds to over 75 pounds at one time
or another. With all types of Optical Tubes.
253mm f/4 Newt
253mm f/6 Newt Only Observatory Mounted
279mm f/10 SCT
200mm f/1.5 Schmidt Camera - No guiding needed with this setup <g >
106mm Tak FSQ
Note: I also owned at the same time a Losmandy GM100 which was a far
better mount. Better tracking, more payload capacity and better guiding
because it had a tangent arm in Dec. IMO the Dec axis is the weak point
in the G-11.
>
>> The Takahashi has, IMO, better (lower) periodic error and they are much
>> less trouble to fiddle with.
>
> I've used the Tak mount only briefly, but I was impressed. How long
> have you owned EM-200? How much weight is it carrying? Would you buy it
> again?
It wasn't mine. But I tried to buy it from him. I liked it a lot. But as
it turns out it isn't the greatest mount for Robotic or computer
controlled operation which I was interested in so that might have been a
good thing.
>
>> Take a look at the AP900 Mount or the newer one that they have out...
>
> The OP says that a mount costing about $4k will be "a significant
> investment" for him, and you're recommending a mount that costs $8,000?
He wanted information and I provided it. He can make the decision to
ignore an AP mount if he wishes. But a complete AP900 can be had for a
lot less than $8,000.00 and the newer Mach One is even less and still
every bit as capable from what I hear.
Another Note: After I had made the decision to sell the G-11 I was
taking some last images with it (253mm f/6 Newt ~60lbs payload) and the
tracking was truly sub arc second for literally hours. The tracking
graph at a 1 pixel scale was flat. I think it was trying to convince me
not to sell it as it was happy in my observatory <g >. But I needed more
payload capacity than what the G-11 actually provides. And better
consistency in an unsheltered environment. Read as "dark sky location"
Bill
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Date: 17 Jul 2007 20:37:18
From: gobbletwo
Subject: Re: Mounts: EM-200 vs. G-11
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Jonathan Tomshine wrote:
> I've been shopping for a portable equatorial mount with go-to that is also
> stable enough & has low enough periodic error for astrophotography --
> something sturdy enough to hold a 100-130 mm refractor or a 10" SCT or
> Mak.
>
> Like so many people, I was drawn towards the Losmandy G-11, but I've
> also been considering the (much more expensive) Takahashi EM-200. I'm
> curious if anyone around here has used both mounts and knows what, if
> anything, the extra cost of the Takahashi buys?
>
> If anyone has insight into this, or any other recommendations beyond the
> G-11 or EM-200, please post a reply. I'll greatly appreciate it, as this
> will be a significant investment for me.
>
> Thanks,
> Jon
The Eq-6 (Orion Atlas G?) will fulfill your requrements, and then some..
jon
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