Author Topic: Which is a better GOTO Mount(Alt/Az or GEM)  (Read 599 times)

Michael Postle

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Which is a better GOTO Mount(Alt/Az or GEM)
« on: December 31, 2017, 04:53:48 AM »
Since I am researching equipment for my next scope a mount is one very important part of the equation.
I want to spend a good deal of time doing planetary observing(Mars and Jupiter)especially. I may consider doing some planetary and lunar imaging in time but that's not written in stone. Also I don't think I will concentrate on many DSO's(except the Messier objects).

So my question is would one type of mount benefit me more then another.
I would love to have a GOTO mount for ease of use and times when I am in light polluted skies. So is one significantly better then the other(GEM or Alt-Az).
Seems as if an Alt-Az would be easier to set up but it also seems as if a GEM would possibly be more solid and offer more options.

Thanks Everyone(You guys are the best)



David Williams

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #1 on: December 31, 2017, 09:54:43 AM »
My most used telescope is an 8" SCT. I could mount it on either an AVX GEM or an Evolution Alt-Az mount (I have both). I almost always go for the Evo.

The Evo:
weighs less
Is simpler to set up
provides a more consistent eyepiece placement
And is delightfully free of meridian flips

The AVX has a slight advantage in stability with a c8, but I can honestly say that Evo is close enough that I don't ever find myself wishing I had used the AVX instead. Of course, the AVX also has an advantage on max payload. And, of course, it is an equatorial mount. It cab also handle scopes that would not be practical on the Evo due to clearance issues.

lehroldwebbdep

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #2 on: December 31, 2017, 10:29:15 AM »
The goto alt-az mount I had the most experience with was a Meade ETX 90. With an equatorial mount you do have the option of later doing AP. In my opinion the ETX 90 and the AVX were fairly similar in ease of use. I would give the nod to the Meade product based on the visibility and ease of use of their controller. I have difficulty reading the AVX controller. More my bad eyes, then Celestrons fault though. Many of the people who have bought the AVX for AP have later decided to upgrade to a better mount.

tirafarpa

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #3 on: January 04, 2018, 06:48:40 PM »
Since you're primarily an observer and have said you'll only be doing planetary/lunar imaging (short exposure) I'd recommend an Alt-az. Far easier to set up, and far more conducive to observing.

Daniel Johnson

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #4 on: January 08, 2018, 01:09:03 AM »
For planetary viewing... I don't think a goto is important... the planets, at least the studyable ones (especially for a low payload mount) are easy to find... the goto helps for DSO's... Alt/Az is easier, but then you don't get the tracking time for AP unless you do a wedge which to me is a royal pain...

An Alt/Az is easier to set up, but I'm kinda thinking that is marginal nowadays... For an EQ, for visual you kinda just set the proper alt with the dial and point it North... and if you do the full PA with a PAS, and a multistar alig, that generally takes 5 or 10 minutes so not a biggie anyway...

If you are wanting planetary... you may be dealing with fairly good size scopes... so to me, an AVX is out. With mine, I do visual with my 60mm and 80mm refractors, but would never consider using my 127mm on it... and even though they advertise it, a 6" Newt or an 8" SCT is really more than pushing it... my VX is my grab n go mount...

To me... the bottom of the acceptable line mount would be an Orion Sirius or the SkyWatcher EQ5 equivalent... the Celestron AVX and iOptron ZEQ25 are fine for very light payload visual and non-critical AP for light weight scopes and as a grab-n-go mount...

You are going to hear LOTS of differing opinions... I went to a number of star parties for hands on before I selected my mounts... Orion/SkyWatcher won out over CGEM...

Travis Kuhlman

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #5 on: January 11, 2018, 09:16:17 AM »
Quote
Since I am researching equipment for my next scope a mount is one very important part of the equation.
I want to spend a good deal of time doing planetary observing(Mars and Jupiter)especially. I may consider doing some planetary and lunar imaging in time but that's not written in stone. Also I don't think I will concentrate on many DSO's(except the Messier objects).

So my question is would one type of mount benefit me more then another.
I would love to have a GOTO mount for ease of use and times when I am in light polluted skies. So is one significantly better then the other(GEM or Alt-Az).
Seems as if an Alt-Az would be easier to set up but it also seems as if a GEM would possibly be more solid and offer more options.

Thanks Everyone(You guys are the best)

You are likely to find that there is a pretty sharp line between those who favor Alt az, vs GEQ configurations. With respect to goto, either will work well for your interests, and it is great that you have thought about that in making your choice.

For goto systems, the basic difference in use is that the GEQ needs to be polar aligned. For visual and casual planet imaging, just pointing the mount at polaris and getting your altitude set is often good enough. Using a polar scope brings things up another notch. Alt Az systems usually just make you level the mount and sometimes have it pointing south to start. Both configurations require that you know enough of the sky to identify alignment stars the computer uses to build its internal map.

GEQs generally give you more versatility with respect to using different types of telescopes. Many Alt Az mounts tend favor shorter SCT type scopes. larger Meade and Celestron SCT alt az mounts generally are fixed in that the mount and telescope are one piece.

In my own experience, Alt az mounts are INITIALLY more intuitive to use. Just point and shoot. However, with just a LITTLE more effort at the beginning of the learning curve, GEQ's are a really nice solution for tracking and set up becomes as easy as with the Alt az. Recently, a number of mount options have come out that give you the option to do either. Many people are happy with those and If you were considering the Alt az approach, that is the way I would go, unless you want something like a 10 inch or larger SCT. Hope this helps!

JMD

Mayur Wilson

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #6 on: January 12, 2018, 12:11:02 AM »
You don't say how large a scope you plan to get. Alt-Az scopes can get very heavy in larger sizes (CPC 9.25" or 11" for example).

Really, I would get a GEM. The Alt-Az scope will be useless for DSO AP if you ever are so inclined. And I see no benefit of any kind. You will be using GoTo to find your objects, including planets, so the more "natural" orientation of the Alt-Az is useless. As for polar alignment, that really takes no time at all unless you need to do DSO AP, because a very rough polar alignment is still OK for AP.

Alt-az is a relic of the pre-GoTo era. Strictly for the nostalgia crowd. I also had a fork-mounted SCT, and a manual typewriter as well. I have moved on, however.

Michael Ritchie

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #7 on: January 12, 2018, 09:00:28 AM »
Alt az will be significantly easier. Some alt az mounts have very good GOTO, you'll need to check reviews. For you particular needs, I see no reason for a GEM.

Manish Konakanchi

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #8 on: January 17, 2018, 12:43:31 AM »
I feel for the most part it is just a matter of personal preference when using it for visual.

For many beginners, they don't understand the concepts of how a GEM mount works. So it is frustrating to them to get it aligned.
GEM's come apart into smaller modules making them easier to transport, but more pieces. You can end up with with the eyepiece in an odd location for viewing, but many focusers can be rotated, so this isn't really much of an issue.
Alt/Az mounts have one major draw back. If you have an external focuser, large eyepieces or cameras attached to the back of the scope, they generally will not clear the base of the mount when trying to view objects near zenith.
With a fork mount Alt/Az your scope and mount are basically married together for life. So you can't change scopes. When you get to larger SCT's these can become quite heavy and cumbersome to move and setup.

blasbunmena

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #9 on: January 20, 2018, 12:57:00 PM »
afaik, fwiw, the OP is purchasing (or considering the purchase of) an F/9+, 1m F.L., Vixen VMC-110l.

<p class="citation">Quote

I want to spend a good deal of time doing planetary observing(Mars and Jupiter)especially. I may consider doing some planetary and lunar imaging in time but that's not written in stone. Also I don't think I will concentrate on many DSO's(except the Messier objects).
[/quote]

Zeek Letter

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #10 on: January 21, 2018, 03:16:30 AM »
Quote
You don't say how large a scope you plan to get. Alt-Az scopes can get very heavy in larger sizes (CPC 9.25" or 11" for example).

Really, I would get a GEM. The Alt-Az scope will be useless for DSO AP if you ever are so inclined. And I see no benefit of any kind. You will be using GoTo to find your objects, including planets, so the more "natural" orientation of the Alt-Az is useless. As for polar alignment, that really takes no time at all unless you need to do DSO AP, because a very rough polar alignment is still OK for AP.

Alt-az is a relic of the pre-GoTo era. Strictly for the nostalgia crowd. I also had a fork-mounted SCT, and a manual typewriter as well. I have moved on, however.

&gt;&gt;Really, I would get a GEM. The Alt-Az scope will be useless for DSO AP if you ever are so inclined

That sort of seems like saying if I buy a car, I should buy a minivan, just in case I decide to have kids.

A truly AP-worthy mount is a big expense. And they are usually pretty heavy as well. Even if I got into AP enough to need a GEM with more capability than my AVX, I'd still keep the AVX because for visual, it's good enough for even a pretty sizeable scope, and would thus be more portable for all those times I'm NOT doing AP.

&gt;&gt;Alt-az is a relic of the pre-GoTo era. Strictly for the nostalgia crowd.
I don't understand this comment at all. If anything, Alt-az mounts are way more popular as result of goto than they were pre-goto.

50 years ago, about the only place you found alt-az mounts were on the lowest-end refractors. Any decent Newtonian reflector or respectable refractor was on a GEM. And SCTs were on equatorial forks. It wasn't until the advent of goto that alt-az mounts became common at all for SCTs. And the whole dobsonian revolution is based on a specialized alt-az mount. And the popularity of Dobs helped bring into vogue a different category of alt-az mount as well (Twilights, Losmandy AZ8, etc).

I have nothing against GEMs or minivans for that matter (I own two of the former and one of the latter). There are certainly times when both are the right tool for the job. For the solar eclipse, I used a classic equatorial fork-mounted SCT (with a full aperture filter) and a GEM-based long-focus refractor (using projection), and didn't bother with my at-az mounted CATs.

Chaudhari Evans

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #11 on: January 25, 2018, 01:51:57 PM »
&gt;&gt;Alt-az is a relic of the pre-GoTo era. Strictly for the nostalgia crowd.
I don't understand this comment at all. If anything, Alt-az mounts are way more popular as result of goto than they were pre-goto.

I have an old Unistar Deluxe and an FS 128. That is a really free wheeling mount and capable of tracking planets at 260X with a 30 degree eyepiece. Only thing was, I had trouble locating objects. So I used my CG 5 much more.

Now I have figured out how to put setting circles on the Unistar. There is a new encoder out that fits internally on the shafts (CUI AMT102 Encoders). I'll feed that to the Sky Commander which will send it to a little wireless unit that sends the info to my iPad with SkySafari 5+. Now I can just point the scope so the marker on SF lines up with the object. It will be silent. Once set up, I won't have to touch the Sky Commander again. If I lose the object, it can easily be found again on the iPad screen.

After 30 years, I think this will be the setup I've been looking for. Silent and easy and simple.

I'm just waiting for the encoder cable adapters to come from Astro Devices (http://www.astrodevi...essories/name/1) in Australia.

Quas Padilla

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #12 on: January 25, 2018, 10:31:00 PM »
Alt-az is a relic of the pre-GoTo era. Strictly for the nostalgia crowd.

I understand it totally! Concept rather than word for word... the GEM has really advanced... in a sense due to 2 things... 1) the world of AP becoming available to the amateur astronomer and 2) the availability of many types and sizes of scopes available to the consumer...

As mentioned, you can, for the most part, put any type or size amateur scope on an EQ mount... whereas you can't with most Alt/Az fork and 1 arm mounts.... more important now than in the past due to the 2 items above... to me, that kinda gives a bit of functional obsolescence to the fork and 1 arm mounts...

I also would think that those folks that star hop,and recommend learning the sky rather than depend on computer control would also lean toward the GEM because of the alignment process... the way the world turns so to speak...

Ryan Chaudhari

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #13 on: January 26, 2018, 08:42:59 AM »
Quote
Quote

Since I am researching equipment for my next scope a mount is one very important part of the equation.
I want to spend a good deal of time doing planetary observing(Mars and Jupiter)especially. I may consider doing some planetary and lunar imaging in time but that's not written in stone. Also I don't think I will concentrate on many DSO's(except the Messier objects).

So my question is would one type of mount benefit me more then another.
I would love to have a GOTO mount for ease of use and times when I am in light polluted skies. So is one significantly better then the other(GEM or Alt-Az).
Seems as if an Alt-Az would be easier to set up but it also seems as if a GEM would possibly be more solid and offer more options.

Thanks Everyone(You guys are the best)

You are likely to find that there is a pretty sharp line between those who favor Alt az, vs GEQ configurations. With respect to goto, either will work well for your interests, and it is great that you have thought about that in making your choice.

For goto systems, the basic difference in use is that the GEQ needs to be polar aligned. For visual and casual planet imaging, just pointing the mount at polaris and getting your altitude set is often good enough. Using a polar scope brings things up another notch. Alt Az systems usually just make you level the mount and sometimes have it pointing south to start. Both configurations require that you know enough of the sky to identify alignment stars the computer uses to build its internal map.

GEQs generally give you more versatility with respect to using different types of telescopes. Many Alt Az mounts tend favor shorter SCT type scopes. larger Meade and Celestron SCT alt az mounts generally are fixed in that the mount and telescope are one piece.

In my own experience, Alt az mounts are INITIALLY more intuitive to use. Just point and shoot. However, with just a LITTLE more effort at the beginning of the learning curve, GEQ's are a really nice solution for tracking and set up becomes as easy as with the Alt az. Recently, a number of mount options have come out that give you the option to do either. Many people are happy with those and If you were considering the Alt az approach, that is the way I would go, unless you want something like a 10 inch or larger SCT. Hope this helps!

JMD
See, as I said, a pretty clear divide in opinion:-) Everyone is making good points, based on their own experience and interests. Ultimately, you need to figure out what works for you. I think that consistent among these comments is that the addition of computerized goto has made any difference in ease of use for either configuration vanishingly small. I would suggest going to a star party for your local club and check out both designs and ask questions of the owners. See what goes into a polar alignment. Either configuration can be effective and enjoyable for what you want to do, you just need to figure out which approach you like. Not sure what your experience level is, but if you are new to astronomy I think that investing in something like the skyview app on your phone that helps you identify stars in the sky is a good idea. I found this invaluable when I was starting out, to help me find the guide stars.

Good Luck!

JMD

galpaydabta

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Re: Which is a better GOTO Mount(Alt/Az or GEM)
« Reply #14 on: January 31, 2018, 03:06:35 AM »
My divide is a trifle different.

Long exposure AP - definitely GEM.

Visual - there are some alt az mounts available now with excellent GOTO, and reasonable tracking, that are significantly easier to use. The world has improved. &lt;smile&gt;

In some sense it's an outgrowth of the large observatory telescopes. Some use alt az mounts, and sophisticated computer control to make them perform like a GEM.

http://planewave.com...m/#.WfDWMohrx3g

http://abell.as.ariz...st/bigtel99.htm

Not that that technology is suitable for amateur imagers.