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How large of an Observatory mount?

astrophotography
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7 replies to this topic

#1 Trackerthedog

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Posted 04 November 2019 - 11:13 PM

I'm not sure if I should post this in Observatories or in another forum, but I will try it here and see if it is allowed.

 

My observatory is going to house a 110 lb refractor mounted on a 10 Micron GM 3000. This mount is rated for

220 lbs. I have read that for astrophotography, you should have a mount that can carry "at least twice the weight

of your astrophotography setup". The GM 3000 carries "exactly" twice the weight of the refractor - without the added

weight of camera, filter wheel and OAG and Guide camera.

 

I'm wondering if any of you can tell me whether the additional weight of the camera setup and OAG will affect imaging

for me, since it puts the total weight at a little over the recommended ratio.

 

Any experience / response / wisdom you could share about this would be much appreciated.

 

Thank you in advance.



#2 bobzeq25

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Posted 04 November 2019 - 11:34 PM

I'm not sure if I should post this in Observatories or in another forum, but I will try it here and see if it is allowed.

 

My observatory is going to house a 110 lb refractor mounted on a 10 Micron GM 3000. This mount is rated for

220 lbs. I have read that for astrophotography, you should have a mount that can carry "at least twice the weight

of your astrophotography setup". The GM 3000 carries "exactly" twice the weight of the refractor - without the added

weight of camera, filter wheel and OAG and Guide camera.

 

I'm wondering if any of you can tell me whether the additional weight of the camera setup and OAG will affect imaging

for me, since it puts the total weight at a little over the recommended ratio.

 

Any experience / response / wisdom you could share about this would be much appreciated.

 

Thank you in advance.

The simple, but illuminative view is this.

 

The "twice the weight" rule of thumb approximation is very rough.  The weight spec of a mount is whatever the manufacturer wants to say it is.  There are no rules, no standards.

 

In general, the more expensive mount manufacturers are more conservative in rating their mounts.   The inexpensive manufacturers are in a very competitive mass market, they have incentives to push their weight ratings hard.

 

So, I would expect you'd be just fine.

 

One reason the rule is so rough is that weight is not the only thing involved here.  Focal length magnifies mount errors, and success with a mount depends on focal length as it does on weight.  Narrowband work generally involves exposures limited mostly by practical issues, such as having enough subs for good data rejection.

 

If it were me, I'd ask 10Micron.  Their opinion beats the musings of people here who don't have a 3000.  They have incentives to not paint too rosy a picture.



#3 Astrola72

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Posted 05 November 2019 - 12:04 AM

I just gotta ask - a 110lb refractor?! bigshock.gif


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#4 Trackerthedog

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Posted 05 November 2019 - 01:09 AM

110 lb refractor = Telescope Engineering Company 250 mm Triplet Fluorite Apo.

My mother passed away and left me a generous sum of money. I am now able to build

the Observatory that I've wanted for many years.

 

The 10 Micron was recommended by Yuri Petrunin - head of TEC. However Yuri doesn't do 

imaging, just observing ... and designing and building magnificent telescopes.


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#5 brave_ulysses

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Posted 05 November 2019 - 06:05 PM

"portable"

 

http://astrograph.ne...10APO-Refractor


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#6 dmdouglass

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Posted 05 November 2019 - 07:47 PM

lol.gif   Now THAT was funny !

 

And only $ 58,000 +


Edited by dmdouglass, 05 November 2019 - 07:47 PM.


#7 guyroch

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Posted 06 November 2019 - 06:09 PM

That 50% rule does not apply to 10Micron mounts.

 

The rated capacity for 10Micron (and most premium brands) is true weight capacity.  The GM3000 is rated for 220lbs and that is true imaging weight capacity. The GM3000 will handle your TEC250 like there was nothing on it.

 

I must say however... WOW!  You're going to have a setup that most of us can only dream of.  A+.

 

Sorry to hear about your mother :(

 

Guylain 



#8 nimitz69

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Posted 06 November 2019 - 06:35 PM

lol.gif   Now THAT was funny !

 

And only $ 58,000 +

More like $71,000 with current exchange rates ... and only 240 days to ship ...




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