22 replies to this topic

[OneSky]

I'm a newbie that started a few months ago with an AZ-GTi (11lbs payload) and 3" and 4" Astro-Tech refractors. Since I live in a Bortle 8 urban area, using Go-To has been very helpful to learn the night sky. Even here, I can usually see Sirius, Procyon, Capella, etc., do a basic alignment, and then the Go-To can help find at least some DSO to observe (though even on the clearest night, Andromeda was a very faint fuzzball). Not surprisingly, going forward, I'm interested in DSO imaging and/or EAA, as well as grab-n-go visual with larger aperture scopes, like a 5 inch refractor or a C6 or C8 OTA. I had been thinking about the Celestron Evolution mount for the higher payload, visual Go-To (no polar alignment needed) and maybe the Sky-Watcher HEQ5i for a midrange WiFi EQ mount for imaging/EAA. But now, there are these midrange hybrid mounts like the AZ-EQ5 or even more radical AM5 (no counterweights!), that seem to check more boxes...in one mount. With their 30lbs payload, they offer visual observing with larger aperture scopes, as well as easy to use Wi-Fi enabled Alt-Az Go-To. And, as an EQ mount, they offer DSO imaging and EAA capability. Both of those mounts, and the AM5 in particular, also seem to have put lightweight grab-n-go portability as a high priority. For sure, there are those that are mainly interested in astrophotography, as well as those only interested in visual. But does the recent appearance of these hybrid mounts signal manufacturers trying to address those that are interested in both grab-n-go visual and dabbling in astro-imaging/EAA? Hmmm...on the other hand...am I starting to also understand why some experienced pros continue to recommend that 8" Dob?

[OneSky]

This post was "inspired" by a statement at the AgenaAstro.com site: "Hybrid telescope mounts feature the best of both worlds: they can work as an equatorial mount for astrophotography, or be angled parallel to the ground to work as an altazimuth mount for visual observing. Though sometimes more expensive than a dedicated equatorial or altazimuth mount, hybrid mounts are the clear best choice for those who do both astrophotography and visual observing."

 

But can a good hybrid mount replace both a good EQ mount and a good Alt-Az mount? Or is it trying to check too many boxes?

[dnayakan]

I have not used the new hybrid mounts, so comments from those who have might be more useful…

 

There is no actual substantive difference in function between an EQ and an alt-az mount. They both have two axes of rotation. On an alt-az mount, one of the axes of rotation is pointed straight up. On an EQ mount, that axis is pointed at the celestial pole. You can, with some work, therefore, set either of them in either configuration. An alt-az mount with an equatorial wedge that tilts the vertical axis so that it points at the celestial pole becomes an EQ mount. An EQ mount likewise where the axis is tilted in some way so it points straight up becomes an alt-az mount. Put another way, if you were at the north or South Pole, the two mount types become indistinguishable in use. 

 

One way to understand this is to look at the Questar. Set it flat on a table or a tripod and you basically have something like a Dob, an alt-az style mount. Set it up on the Tristand and adjust the tristand head so it points at Polaris and you now have it in EQ style configuration. 
 

Therefore, in my opinion, the difference is really one of ergonomics. An EQ mount is designed to make it easy to use when aligned with the axis of Earth’s rotation. An alt-az mount needs more work to do this - you will need wedges of different angles if you view from different lattitudes etc. Similarly, most EQ mounts may not provide enough adjustment to set up as an alt-az.

 

Cheers, DJ

[Wildetelescope]

This post was "inspired" by a statement at the AgenaAstro.com site: "Hybrid telescope mounts feature the best of both worlds: they can work as an equatorial mount for astrophotography, or be angled parallel to the ground to work as an altazimuth mount for visual observing. Though sometimes more expensive than a dedicated equatorial or altazimuth mount, hybrid mounts are the clear best choice for those who do both astrophotography and visual observing."

 

But can a good hybrid mount replace both a good EQ mount and a good Alt-Az mount? Or is it trying to check too many boxes?

the answer to that question depends on your expectations.  Just starting out, those mounts will likely satisfy you from some time.  Especially for EAA and visual.  If you are imaging at 1000 mm or less, you will likely be just fine for DSO imaging.  Lots of folks use these.   The AM5 mount is fairly new, but it is getting pretty good feedback.  Imaging above 1000 mm, like with a C8 for DSO long exposures(1-5 minutes)  will likely take some practice and optimization of your guiding and set up, but that is true for most mounts in that price range.  EAA with that scope and those mounts should be fine.  Good Luck!  

 

JMD

[Dan_I]

An altaz mode is very useful for Newtonian telescopes (in eq mode the eyepiece is often in ackward position). For other types of telescopes, not so much.

For instance an 8" or 10" newt on an azeq6 is a very good all-around photovisual setup

Edited by Dan_I, 27 March 2023 - 07:02 AM.

[OneSky]

I have not used the new hybrid mounts, so comments from those who have might be more useful…

 

There is no actual substantive difference in function between an EQ and an alt-az mount. They both have two axes of rotation. On an alt-az mount, one of the axes of rotation is pointed straight up. On an EQ mount, that axis is pointed at the celestial pole. You can, with some work, therefore, set either of them in either configuration. An alt-az mount with an equatorial wedge that tilts the vertical axis so that it points at the celestial pole becomes an EQ mount. An EQ mount likewise where the axis is tilted in some way so it points straight up becomes an alt-az mount. Put another way, if you were at the north or South Pole, the two mount types become indistinguishable in use. 

 

One way to understand this is to look at the Questar. Set it flat on a table or a tripod and you basically have something like a Dob, an alt-az style mount. Set it up on the Tristand and adjust the tristand head so it points at Polaris and you now have it in EQ style configuration. 
 

Therefore, in my opinion, the difference is really one of ergonomics. An EQ mount is designed to make it easy to use when aligned with the axis of Earth’s rotation. An alt-az mount needs more work to do this - you will need wedges of different angles if you view from different lattitudes etc. Similarly, most EQ mounts may not provide enough adjustment to set up as an alt-az.

 

Cheers, DJ

Thanks, DJ. Yes, I have an AZ-GTi alt-az mount. As you noted, some have tried to get around its limitations by adding a wedge. That's too much tweaking for me. I'm actually interested in the AZ-EQ5i or AM5 as hybrid mounts they claim to be--out of the box--the best of both worlds, both alt-az for easy go-to visual (no polar aligning required) and astro-imaging in EQ mode. I doing my research.

[OneSky]

the answer to that question depends on your expectations.  Just starting out, those mounts will likely satisfy you from some time.  Especially for EAA and visual.  If you are imaging at 1000 mm or less, you will likely be just fine for DSO imaging.  Lots of folks use these.   The AM5 mount is fairly new, but it is getting pretty good feedback.  Imaging above 1000 mm, like with a C8 for DSO long exposures(1-5 minutes)  will likely take some practice and optimization of your guiding and set up, but that is true for most mounts in that price range.  EAA with that scope and those mounts should be fine.  Good Luck!  

 

JMD

Thanks for the green light to spend more money, JMD (just kidding). You're very right about expectations. As I've found out in just the 3 or 4 months I've owned my scopes, my expectations have changed. For one, I started out just wanting a grab-n-go visual rig and got a 3" refractor. It didn't take long for me to be a bit frustrated in using a 3" refractor purely for visual (in Bortle 8 skies). Then I got a 4" refractor, which is better, but realized to actually see faint DSO, you kind of need to get into some kind of stacking and EQ tracking. My two refractors are 80mm/560mm focal length and 102mm/714mm focal length, so hopefully, either of those hybrid mounts will support them, but also can be used in alt-az mode for just quickly going out on clear nights and not polar aligning. And yes, that AM5 is really interesting. It weighs the same as the Star Adventurer GTi (which I was considering), but has a 30lbs payload and doesn't need counterweights. Oh, and it costs about 3X as much, right?

[OneSky]

An altaz mode is very useful for Newtonian telescopes (in eq mode the eyepiece is often in ackward position). For other types of telescopes, not so much.

For instance an 8" or 10" newt on an azeq6 is a very good all-around photovisual setup

Doesn't that explain the popularity of the Dobsonian alt-az mount? But my particular limitation is I stargaze from my driveway, and it's like a "canyon" bordered by my garage, my roof, and my neighbors roof. Being low, a Dobsonian would have very limited access to the sky. On the other hand, an 8" or 10" Newtonian could be put on a higher alt-az or EQ mount, but don't bigger Newtonians weigh more and require a heavier duty mount (not so grab-n-go)?

[OneSky]

Not sure if anyone is still following this post's question, but if you have experience with both visual observing with alt-az mounts (AZ-GTi, Celestron NextStar, etc) and astro-imaging with equatorial mounts, do you agree that one possible drawback to a hybrid mount is that it might actually not be such a good idea?

 

Visual and astro-imaging are different setups. And, with a hybrid mount; converting from say, EQ to alt-az, involves more than just lowering the wedge down to zero. Wouldn't you need to replace the astro camera with a diagonal and eyepiece, maybe add a red dot finder? Maybe remove the ASIAir, guide scope, guide camera? Maybe rebalance the scope and counterweights?

 

Sure, it's a bit more expensive, but might it be a better long-term strategy to have two mounts sort of permanently setup, one alt-az for quick Go-To and one EQ mount for imaging? For example, for my 3" refractor, just a Star Adventurer GTi (the head is only $640) would be fine for imaging, and for visual, maybe the popular Celestron Nexstar or Evolution 8 (which I could also put my 4" refractor on).

 

Any thoughts?

[psandelle]

It really depends on if you want to image and view at the same time. If so, then a hybrid is only one mount, so that won't work. If you are going to do EITHER imaging or viewing, then the gauge of a hybrid mount is on how well it tracks when guided (and something like the Rainbow Astro guides well), as imaging will be the bar you need to clear. Me, I am almost 100% imager, but I will do some solar viewing, and/or using my bigazz binocs when I'm imaging. So, I have multiple mounts (the 10Micron for major imaging; the Rainbow Astro for a second mini-rig; the iOptron for viewing, solar or binocs). So, it really depends on what you want to do. If you're going to do things separately, a hybrid mount can be just the ticket (especially if you want a good imaging mount and save money by not getting a second mount for visual).

 

Paul

[OneSky]

It really depends on if you want to image and view at the same time. If so, then a hybrid is only one mount, so that won't work. If you are going to do EITHER imaging or viewing, then the gauge of a hybrid mount is on how well it tracks when guided (and something like the Rainbow Astro guides well), as imaging will be the bar you need to clear. Me, I am almost 100% imager, but I will do some solar viewing, and/or using my bigazz binocs when I'm imaging. So, I have multiple mounts (the 10Micron for major imaging; the Rainbow Astro for a second mini-rig; the iOptron for viewing, solar or binocs). So, it really depends on what you want to do. If you're going to do things separately, a hybrid mount can be just the ticket (especially if you want a good imaging mount and save money by not getting a second mount for visual).

 

Paul

Great point, Paul. I've never done astro-imaging (yet), but it sure seems like you'd have time to casually stargaze while your imaging rig and software collect the hours and hours of data. Also, to your point about the "tracking bar," I wonder if the "jack of all trades, master of none" cliche applies to hybrid mounts. Maybe that's not fair, as they do fill a certain niche; the AZ-EQ5 for example also has a 3rd mode of carrying two scopes simultaneously for outreach at star parties, etc. But yes, I wonder about the tracking accuracy (is it PE?) of hybrid versus EQ-only mounts.

[davidgmd]

 

There is no actual substantive difference in function between an EQ and an alt-az mount. They both have two axes of rotation. On an alt-az mount, one of the axes of rotation is pointed straight up. On an EQ mount, that axis is pointed at the celestial pole. You can, with some work, therefore, set either of them in either configuration. An alt-az mount with an equatorial wedge that tilts the vertical axis so that it points at the celestial pole becomes an EQ mount. An EQ mount likewise where the axis is tilted in some way so it points straight up becomes an alt-az mount. Put another way, if you were at the north or South Pole, the two mount types become indistinguishable in use. 

 

Cheers, DJ

 

"In theory there is no difference between theory and practice - in practice there is" (Yogi Berra)

[psandelle]

Great point, Paul. I've never done astro-imaging (yet), but it sure seems like you'd have time to casually stargaze while your imaging rig and software collect the hours and hours of data. Also, to your point about the "tracking bar," I wonder if the "jack of all trades, master of none" cliche applies to hybrid mounts. Maybe that's not fair, as they do fill a certain niche; the AZ-EQ5 for example also has a 3rd mode of carrying two scopes simultaneously for outreach at star parties, etc. But yes, I wonder about the tracking accuracy (is it PE?) of hybrid versus EQ-only mounts.

Strain Wave Gear mounts (like the Rainbow Astros), though different in how they guide, are very, very good imaging machines (they guide well). They are a little more expensive because their strongest points are their light weight per load capacity, and they usually don't need any counterweights. But, generally speaking, they guide as well as any strictly EQ mount in their capacity range. I've done LOTS of imaging with them, and they're great!

Paul
 

[OneSky]

Strain Wave Gear mounts (like the Rainbow Astros), though different in how they guide, are very, very good imaging machines (they guide well). They are a little more expensive because their strongest points are their light weight per load capacity, and they usually don't need any counterweights. But, generally speaking, they guide as well as any strictly EQ mount in their capacity range. I've done LOTS of imaging with them, and they're great!

Paul
 

 

 

"In theory there is no difference between theory and practice - in practice there is" (Yogi Berra)

Paul and davidgmd,

 

Thanks very much for the (re)clarification; no substantive difference between an EQ and alt-az mount. Each can theoretically become the other, and not surprisingly, Sky-Watcher and ASI decided to make mounts that are designed to be either. But are there less substantive differences, some which might tilt one's purchase? For example, it was noted in one review of the AZ-EQ5i that one of the compromises made for its hybrid ability was they had to omit the built-in polarscope. I believe that's a popular feature of Sky-Watcher's EQ only mounts like the Star Adventurer GTi and HEQ5i. And reviews of the AM5 note that it also lacks a polarscope.

 

But in any case, my question is, if a mount is relatively easy to polar align--and you'd get better at it over time, right?--maybe getting a hybrid mount capable of both EQ and alt-az isn't as important as getting a mount with EQ-friendly features. Besides, my primary interest is in faint DSO which (unless one has a huge Dobsonian), seems to require an EQ mount that allows for collecting hours of light data. So that imaging-capable EQ mount, whether EQ only, or hybrid, can essentially become your one main mount. I was leaning towards a hybrid mount with 30lbs payload, but I think I'm shifting my priority more towards getting a good tracking EQ mount (with 30lbs payload).

[davidgmd]

OneSky, I see what you mean.  If you’re doing AP on DSOs, you definitely want a mount with EQ capabilities.

   

For visual, regardless of theory, eyepiece placement alone is a big difference in the practical use of an EQ vs. alt/az mount. That’s all I was trying to say with my Yogi-ism.

 
A mount that can do both would seem to have an advantage. I’m not familiar enough with them, or AP in general, to know if they are as good at AP as a dedicated EQ mount.
 
 

[Wildetelescope]

Paul and davidgmd,

 

Thanks very much for the (re)clarification; no substantive difference between an EQ and alt-az mount. Each can theoretically become the other, and not surprisingly, Sky-Watcher and ASI decided to make mounts that are designed to be either. But are there less substantive differences, some which might tilt one's purchase? For example, it was noted in one review of the AZ-EQ5i that one of the compromises made for its hybrid ability was they had to omit the built-in polarscope. I believe that's a popular feature of Sky-Watcher's EQ only mounts like the Star Adventurer GTi and HEQ5i. And reviews of the AM5 note that it also lacks a polarscope.

 

But in any case, my question is, if a mount is relatively easy to polar align--and you'd get better at it over time, right?--maybe getting a hybrid mount capable of both EQ and alt-az isn't as important as getting a mount with EQ-friendly features. Besides, my primary interest is in faint DSO which (unless one has a huge Dobsonian), seems to require an EQ mount that allows for collecting hours of light data. So that imaging-capable EQ mount, whether EQ only, or hybrid, can essentially become your one main mount. I was leaning towards a hybrid mount with 30lbs payload, but I think I'm shifting my priority more towards getting a good tracking EQ mount (with 30lbs payload).

You can image with any mount.  Any Alt az mount can be turned into an EQ with the addition of a wedge.   Most folks image with an EQ mount, but there are a lot of nice images that have been generated with the Celesrtron and Meade Alt az mounts over the years(think LX200).   I started imaging with an Ioptron minitower and short exposures, which is what folks call EAA now a days.   It worked fine for planets, moon and bright DSO’s.  Things become more interesting when you are looking at fainter stuff.  The Pleiades are one example.  I was not able to pull out any real Nebulosity until I started guiding on an EQ mount.   Cameras are more sensitive, but at some point you DO benifit from being able to take longer exposures.   The main question regarding the hybrid mounts is what are your tolerances for PE.  If you start imaging at Longer focal lengths, then you might find yourself challenged.  But for imaging under 1000mm, like your scopes, a hybrid EQ5 or EQ6 class of mount would likely serve you just fine, for quite a while.  

 

Cheers!

 

JMD

[psandelle]

Never once used my SWG mounts (like the Rainbow Astros) in alt/az; I only used them for imaging. They are equivalent to any other "just EQ" mount in that department, except they're lighter and don't need counterweights unless you're pushing their limit. If you need to do visual as well as imaging with one mount, get the hybrid mount. If not, you might STILL get the hybrid mount, at least the SWG mounts, because they are smaller and lighter and still take a similar load to non-SWG mounts in that range.

 

Almost everyone does polar alignment with something like SharpCap or PoleMaster these days; not so much polar scopes, so no need to have them anymore.

 

I think that's about it. If you need only one mount for both visual and imaging, get the hybrid. If you want the lightest and smallest mount for imaging alone, get a SWG mount (which is probably going to be a hybrid as well). If you want a less spendy imaging-only mount, find a pure non-SWG EG-only mount.

 

Paul

[OneSky]

Thanks everyone, lots of great advice from you all!

 

Ironically, I started this hybrid mount thread, but because of your feedback, I now think a mount doesn't so much score points for being hybrid but, as you guys said, for its tracking accuracy. And because of new software/hardware, as one of you said, polar aligning is easier these days. This is another factor that makes me think the advantages of an EQ mount's allowing for longer exposures (for faint DSO) more than makes up for any difficulty in polar aligning and mount setup.

 

Another factor tilting things away from a hybrid mount is the simple fact that under my Bortle 8 skies, there's only so much you can see with an alt-az mount. Also, good ol' Mother Nature is a factor. Since I got started in star-gazing last December, I can count on one or maybe two hands, the number of really good seeing nights. As one of you with a hybrid mount said, you hardly ever use its alt-az capability. To really see the interesting DSO, it seems to require the benefit of an EQ mount.

 

My short list is an AM5 (or other strain wave mount). If going with Sky-Watcher (I do like their SynScan app), instead of the AZ-EQ5, I think I'd go with their EQ-only HEQ5i. Both the AM5 and HEQ5i have 30lbs payloads.

[OneSky]

I guess the shortlist now should include the new ZWO AM3 (17.5lbs payload, $1499, weighs 8.5lbs).

[jebinc]

OneSky, I see what you mean.  If you’re doing AP on DSOs, you definitely want a mount with EQ capabilities.

   

For visual, regardless of theory, eyepiece placement alone is a big difference in the practical use of an EQ vs. alt/az mount. That’s all I was trying to say with my Yogi-ism.

 
A mount that can do both would seem to have an advantage. I’m not familiar enough with them, or AP in general, to know if they are as good at AP as a dedicated EQ mount.
 
 

 

Is this universally true?  What if you have a RASA or fast f/2 Hyperstar v4 setup, and stack short (say 15s-25s) sub frames, using a quality Alt-Az?

Edited by jebinc, 03 March 2024 - 10:00 AM.

[davidgmd]

Is this universally true?  What if you have a RASA or fast f/2 Hyperstar v4 setup, and stack short (say 15s-25s) sub frames, using a quality Alt-Az?

  
Even with short subs, if stacking over a long period of time with an AZ mount you’ll have to derotate.

[jebinc]

Thanks. How would you define, “over a long period of time”?

[Celerondon]

Thanks. How would you define, “over a long period of time”?

This source says a minute or thereabouts. 
 

Don