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Dual AZ/EQ mounts
Posted: Fri Feb 07, 2020 12:34 am
by John in SC
Hi all, relative newbie here. Have a Nexstar 8se and realize that if I want to pursue astroimaging I will need to add hardware, software and knowledge. I have seen some mounts (Skywatcher and Orion, e.g.) that have dual altazimuth and equatorial capabilities. Is there a disadvantage to using an EQ mount for lunar or planetary imaging? What is the advantage of having both? Would a great GoTo EQ mount not be sufficient for both? Thanks!
Re: Dual AZ/EQ mounts
Posted: Fri Feb 07, 2020 1:59 am
by Bigzmey
GoTo EQ make better astrophotography mounts than AltAz, no matter if it is Lunar/planetary or DSO. I would just get the best EQ GoTo mount you can afford and don't worry about dual mode.
Re: Dual AZ/EQ mounts
Posted: Sun Feb 09, 2020 7:52 pm
by BigKahuna
Although not a full EQ mount, you can purchase (or build) a wedge for your 8SE. The Celestron Wedge will run about $300 to $400 but you can build your own wedge for about $50 in parts. This should get you 1 - 2 minute or so exposures. It's a "decent" upgrade but not near a good as an EQ mount. The setup for using a wedge for the 8SE seems complicated. YouTube has a few people that show the process of both building and the alignment procedure. "Baltier"
Is one of the guys whose videos you should watch
I made a wedge for my 8SE but then purchased an AVX so I never tried it. The shortfall of the 8SE is the 8" OTA is pushing the weight limit of that mount with the single arm YMMV
The 8SE mount is perfect for viewing/imaging the solar system as you dont need long exposures (longer than 20 - 30 second max). It's when you want to image Deep Sky images that the drawback of that az/alt mount will hinder you.
Re: Dual AZ/EQ mounts
Posted: Thu Feb 13, 2020 9:21 am
by Viktorious
I myself am looking to buy a AZ-EQ5 (i.e. Skywatcher's combined). As already stated, yes you can use an
EQ mount for everything.
The "advantage" of having both is that
alt-az is easier and faster to set up, just put it down and align. As mentioned
EQ deals with field rotation and is thus always needed for longer exposures. Setting up takes more effort as polar alignment is needed, the more detailed the better.
EQ is not necessary for visual astronomy or solar system photography.
So with a combined mount you can decide which mode to use depending on the "usage of the session". If it's a visual session or solar system photography you can set up in
alt-az. If it's a
DSO imaging session with long exposures you can setup in
EQ.
Don't know where you're situated but here's a table with "longest possible" exposure times in
alt-az before field rotation becomes noticeable.
Re: Dual AZ/EQ mounts
Posted: Thu Feb 13, 2020 9:35 am
by Viktorious
Edit to my previous post. Realized I pasted the table for my latitude area. On this page you can see the table for all latitudes and some other information about photography with
alt-az.
https://telescopemount.org/short-exposu ... t-results/
Re: Dual AZ/EQ mounts
Posted: Thu Feb 13, 2020 7:38 pm
by Bigzmey
Viktorious wrote: ↑Thu Feb 13, 2020 9:21 am
I myself am looking to buy a AZ-EQ5 (i.e. Skywatcher's combined). As already stated, yes you can use an EQ mount for everything.
The "advantage" of having both is that alt-az is easier and faster to set up, just put it down and align. As mentioned EQ deals with field rotation and is thus always needed for longer exposures. Setting up takes more effort as polar alignment is needed, the more detailed the better. EQ is not necessary for visual astronomy or solar system photography.
So with a combined mount you can decide which mode to use depending on the "usage of the session". If it's a visual session or solar system photography you can set up in alt-az. If it's a DSO imaging session with long exposures you can setup in EQ.
Don't know where you're situated but here's a table with "longest possible" exposure times in alt-az before field rotation becomes noticeable.
post-316058-0-39712300-1580980680.png
This is really depends on how well the mount executed. I don't have experience with AZ-EQ5, but I have
SW AzGti mount which is also a dual mode mount. It tries to do both modes, but does not do either with 100% efficiency. Is it badly designed hardware or half-baked software? Who knows.
BTW
SW GtiAz uses the same
app/soft as AZ-EQ5. So I would really check feedback on forums before committing to it.
On the other hand a straight
EQ mount like
CGEM is a mature product in the same price range with AZ-EQ5 but with higher load capacity.
Re: Dual AZ/EQ mounts
Posted: Thu Feb 13, 2020 9:17 pm
by Viktorious
Bigzmey wrote: ↑Thu Feb 13, 2020 7:38 pm
This is really depends on how well the mount executed. I don't have experience with AZ-EQ5, but I have SW AzGti mount which is also a dual mode mount. It tries to do both modes, but does not do either with 100% efficiency. Is it badly designed hardware or half-baked software? Who knows.
BTW SW GtiAz uses the same app/soft as AZ-EQ5. So I would really check feedback on forums before committing to it.
On the other hand a straight EQ mount like CGEM is a mature product in the same price range with AZ-EQ5 but with higher load capacity.
Huh I didn't know that about the AZ-Gti! Still only listed as
alt-az on the pages I shop from. I see there are some posts about a firmware upgrade though (and YT videos). Still, feels like the base design of the AZ-EQ5 vs the Gti is completely different. So I hope I don't experience any of that behavior.
Anyway, I'm going with the AZ-EQ5 as I'm looking for a lighter mount (7,7 kg), the
CGEM is 20 kg. Also price difference of 500-600 € is a lot for me! But yes I've done a lot of reading and also created a topic on CN where the AZ-EQ5 got good recommendations.
I'm pestered by cloudy nights (real ones, not forums) so I live on the forums at the moment
.
Re: Dual AZ/EQ mounts
Posted: Thu Feb 13, 2020 9:50 pm
by Bigzmey
Viktorious wrote: ↑Thu Feb 13, 2020 9:17 pm
Bigzmey wrote: ↑Thu Feb 13, 2020 7:38 pm
This is really depends on how well the mount executed. I don't have experience with AZ-EQ5, but I have SW AzGti mount which is also a dual mode mount. It tries to do both modes, but does not do either with 100% efficiency. Is it badly designed hardware or half-baked software? Who knows.
BTW SW GtiAz uses the same app/soft as AZ-EQ5. So I would really check feedback on forums before committing to it.
On the other hand a straight EQ mount like CGEM is a mature product in the same price range with AZ-EQ5 but with higher load capacity.
Huh I didn't know that about the AZ-Gti! Still only listed as
alt-az on the pages I shop from. I see there are some posts about a firmware upgrade though (and YT videos). Still, feels like the base design of the AZ-EQ5 vs the Gti is completely different. So I hope I don't experience any of that behavior.
Anyway, I'm going with the AZ-EQ5 as I'm looking for a lighter mount (7,7 kg), the
CGEM is 20 kg. Also price difference of 500-600 € is a lot for me! But yes I've done a lot of reading and also created a topic on CN where the AZ-EQ5 got good recommendations.
I'm pestered by cloudy nights (real ones, not forums) so I live on the forums at the moment
.
What scope do you plan to use with AZ-EQ5? I don't think it will handle C9.25 well.
Re: Dual AZ/EQ mounts
Posted: Fri Feb 14, 2020 8:40 am
by Viktorious
Visually and solar system photography the C9.25. No issue at 10 kg weight versus the rated 15-18 kg payload. The Evolution is rated at 11 kg... Then as I slide into more serious AP I'll get a small refractor (80-102 mm) for wide field DSOs.
Of course as I save up for the frac I'll be using the C9.25 for everything to get as much practice as possible. Perhaps I should note that I use the C9.25 at f/6.3 for basically everything but planets. At f/10 I can agree that it would be a different type of pain.
.