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EQ Mount Selection Dilemma

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#1 WyattDavis

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Posted 06 December 2018 - 04:14 PM

I am in the process of trying to select an equatorial mount that can be used for visual and for “casual astrophotography.” I have looked at the Celestron CG-4 (+ motor drive package), AVX, CGEM; the Orion Sirius and Atlas EQ-G; the Losmandy GM8S; and the Skywatcher EQ3-2 with the "Advanced" tracking motor package that includes a ST4 port for guiding (Teleskop-Express offers this).

 

Concerning visual, I am really not interested in GOTO (I have darkish skies in my backyard and have plenty of stars from which to hop) and would be very happy pushing to, using finder scopes, and then locking the clutches/tracking. My primary motivation here is to start using the equatorial coordinate system for reference (all of my other mounts are Alt/Az) and to have basic tracking available. If it were not for the idea of doing AP, the regular slow control knobs would probably be all I would want and I would skip tracking motors completely. Of the amounts above, it looks like only the CG-4, Orions, and the Losmandy have setting circles, but I have read that circles of the size that come on these mounts may not be very useful anyway and that finders are better.

 

Concerning AP, I am responding to an ongoing request from my wife for pictures! I am a bit adverse to using too many electronics in the field, but I am going to give AP a try and see if I end up liking it. This mount would be used with my Celestron C6 SCT (with reducer/corrector), Vixen ED81s (with reducer/corrector), plus a DSLR camera (a Canon 50D + BackyardEOS). I would also probably use the mount with just the DSLR camera body + lens. I am a total beginner at AP and would be going after larger/brighter deep sky objects as a start – including very wide field/Milky Way, star clusters, galaxies, and nebula. I believe that if I use the DSLR as a camera with lens than any of these mounts would work for DSLR wide-field AP - including the CG-4. If I move to DSLR + telescope, it seems like the need for guiding would probably come into play fairly quickly. My plan is to start WITHOUT guiding and see how I like AP before acquiring any additional equipment, but if I do end up enjoying AP then it seems like having a mount that supported guiding might be a good idea.

 

If I don't like AP, I would like to end up with a good EQ mount that can be used for visual without having to use GoTo. The CG-4 and the GM8S both look like they might be workable solutions, even though they are in totally different classes of capacity/quality. 

 

Regarding all of these mounts, I would like to keep the weight down as much as possible and only buy as much mount as I need for the equipment outlined above. And, cost is a consideration. The Losmandy GM8S looks like a high-quality solution for what I am trying to do, but by the time you add a polar alignment scope it is much more expensive than the other options I have identified so far -- probably more than I want to spend.

 

Some questions:

  • The Orion Sirius EQ-G does have setting circles that look larger than those on the CG-4 and GM8S but it also has a GoTo controller. Can I use this mount to track by just polar aligning it and then pushing to targets and tracking or do I have to go through a GoTo alignment as well/use GoTo to use it? (Said differently, could I just use the direction buttons + tracking on it rather than having to use all of the GoTo features?)
  • Would the setting circles on any of these mounts be of any practical use in getting into the general vicinity of targets?
  • If the setting circles on the Sirius EQ-G aren’t very useful anyway, would I be better off falling back to the AVX for my intended applications?
  • Could the CG-4 work for what I am describing above or will I find it immediately limiting if I do end up liking AP?]=

I would really appreciate some experienced perspectives here. Thanks!


Edited by WyattDavis, 06 December 2018 - 04:18 PM.


#2 WadeH237

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Posted 06 December 2018 - 04:30 PM

Regarding your plan for astrophotography, starting with a DSLR/lens and shooting very wide field is a great way to start.  Given your background, I would not select a mount based on AP needs.  I don't have any experience with a CG-4, but it you could probably get decent results with a DSLR and 50mm to 100mm lens.

 

Regarding setting circles, I think that once you get used to the mount, you won't use the setting circles.  The goto functions on these mounts are pretty easy, and they will definitely get you as close, or closer, that you'd get with setting circles.  As for manual operation, the best that you could do would be to polar align the mount and let it track without doing a goto alignment.  You could then release the clutches, move the mount, and retighten the clutches.  For slow motion, you would just use the buttons on the hand controller.  But again, once you get used to goto, you will probably find that you like it.


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#3 Mike G.

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Posted 06 December 2018 - 04:41 PM

not even sure I should jump in here since I don't do any AP, but the CG4 has been my grab and go mount for years. I have the drive kit but only installed the RA motor to keep the mount as small as possible going into and out of my car.  it's a true workhorse and in my opinion, the best non-go-to lightweight EQ mount you can buy, provided you get it with the tubular steel legs and not the aluminum tripod.  since it's not go-to, I use the polar scope then push to my target, lock the clutches and turn the drive on.  I have used it with my 6" SCT, 8" SCT and my 8" f5 newt.  it just works.  before I had the CG4, I used to drag the CG5 around.  that stopped immediately when I got the CG4.  lighter, smaller form factor and less things hanging off the mount to break.  as far as the setting circles, they are small and very hard to read in the dark (even with a red LED) but with sky safari and various atlases, I never felt I needed them anyway.

 

good luck with your quest!


Edited by Mike G., 06 December 2018 - 04:41 PM.

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#4 jimr2

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Posted 06 December 2018 - 04:52 PM

Wyatt,

 

Since it seems to be your spouse who wants pictures, maybe you should buy her a mount to do AP with--complete w/ GoTo, etc--and get yourself something smaller/lighter/simpler/non-GoTo for just visual use?? You already seem to have all the scopes you'd need to do both, using either mount?! Just a thought...

 

-jim-


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#5 WyattDavis

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Posted 06 December 2018 - 05:30 PM

Wyatt,

 

Since it seems to be your spouse who wants pictures, maybe you should buy her a mount to do AP with--complete w/ GoTo, etc--and get yourself something smaller/lighter/simpler/non-GoTo for just visual use?? You already seem to have all the scopes you'd need to do both, using either mount?! Just a thought...

 

-jim-

Now there is some out-of-the-box thinking! Realistically, I think she is more interested in the product and not the process.  :^)



#6 WyattDavis

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Posted 06 December 2018 - 05:35 PM

not even sure I should jump in here since I don't do any AP, but the CG4 has been my grab and go mount for years. I have the drive kit but only installed the RA motor to keep the mount as small as possible going into and out of my car.  it's a true workhorse and in my opinion, the best non-go-to lightweight EQ mount you can buy, provided you get it with the tubular steel legs and not the aluminum tripod.  since it's not go-to, I use the polar scope then push to my target, lock the clutches and turn the drive on.  I have used it with my 6" SCT, 8" SCT and my 8" f5 newt.  it just works.  before I had the CG4, I used to drag the CG5 around.  that stopped immediately when I got the CG4.  lighter, smaller form factor and less things hanging off the mount to break.  as far as the setting circles, they are small and very hard to read in the dark (even with a red LED) but with sky safari and various atlases, I never felt I needed them anyway.

 

good luck with your quest!

I'm pretty sure the CG-4 would be a good fit for the visual parts of this and do think using my standard visual finder scopes would be pretty natural for me. I think it would also work just fine for the DSLR + camera lens part - and with just the RA motor as you describe. Very tempting to just call that the limits of my AP adventures and go with simple, lightweight and low cost...

 

But, the questions that address doing a bit more on the AP side, I'm still curious as to how far I would get with a CG-4 before maxing it out.



#7 WadeH237

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Posted 06 December 2018 - 07:57 PM

But, the questions that address doing a bit more on the AP side, I'm still curious as to how far I would get with a CG-4 before maxing it out.

The answer is:  Not very.

 

It would be ok for the DSLR with a reasonable focal length lens.  Beyond that, the AVX is generally the *minimum* mount I would recommend for doing deep sky astrophotography.

 

So here is my rationale for my responses on this topic:  Deep sky astrophotography is hard.  Really hard.  I won't go into the details, but you can cruise one of the imaging forums for the gory details that go beyond the mount discussions that we have in this forum.

 

I figure that one of two things will happen:  You will get bitten by the imaging bug and begin a long, expensive journey.  Or, you will find that it's not for you (based solely on what I've read in this forum, I suspect that this is the more likely outcome because there is way too much work involved, if you are doing to make someone else happy - but I've been wrong more often than right when trying to predict the future...)

 

If you find that you don't want to pursue astrophotography, you will have a mount that suits what you are doing, and won't be stuck living with a mount that's too heavy and too expensive.  If you do decide that you want to pursue astrophotography more seriously, that's the time to look at upgrades - and their associated expense).


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#8 mjt24073

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Posted 06 December 2018 - 09:05 PM

I have an eq3 (similar to the cg4 with lighter legs) and a GM8.  The eq3 is light and easy to carry outside for a light scope like an 80mm apo style scope.  I routinely use a TV85 on mine for visual, and it works nicely.  The setting circles are near useless - small, imprecise, and they don’t alway move smoothly with the mount.  The GM8 however, has quite usable setting circles.  I use them with my C8 and can at a minimum get an object in the finder, if not in the scope’s field of view.  The setting circles are large enough, and move smoothly with the mount.  I use them all the time with good success.  The mount is a bit heavier, and requires a battery tank to run, as opposed to the D cells on the eq3’s RA drive.  I’m strictly visual, and do not like go to, but if I were to try photography, I wouldn’t hesitate with the GM8, but wouldn’t even bother with the eq3.  

 

So, if you have a small scope and are strictly visual, the cg4 may be just fine.  With a good polar alignment and wide field short exposures, you may be able to play with the cg4.  In my experience, it doesn’t take a great Astro photo to impress your non-astronomy friends.  If you want a very nicely made mount for visual, with nice setting circles, that you could use for occasional photography with capabilities that you can grow into, then go for the GM8.  


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#9 alphatripleplus

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Posted 07 December 2018 - 09:35 AM


 

So here is my rationale for my responses on this topic:  Deep sky astrophotography is hard.  Really hard.  I won't go into the details, but you can cruise one of the imaging forums for the gory details that go beyond the mount discussions that we have in this forum.

 

I figure that one of two things will happen:  You will get bitten by the imaging bug and begin a long, expensive journey.  Or, you will find that it's not for you (based solely on what I've read in this forum, I suspect that this is the more likely outcome because there is way too much work involved, if you are doing to make someone else happy - but I've been wrong more often than right when trying to predict the future...)

 

Excellent points.



#10 seasparky89

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Posted 07 December 2018 - 10:21 AM

My Atlas Mount was one of thr early ones that did not have go-to.  I learned to use the reasonably large setting circles with good success.  Now I have full go-to on that mount, and I love it.  However, at times I do revert to the manual setting circles just for kicks and also to retain my proficiency in using them (could be a life saver for me if my power supply gives out).  And, yes, one can use the hand controller in a non go-to mode.  I think the setting circles on the Serius are a bit smaller, but still usable.

 

Stan



#11 baron555

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Posted 07 December 2018 - 10:23 AM

GM-8 and don't look back.  You'll be happy you put your money into a good mount.


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#12 JAC51

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Posted 07 December 2018 - 10:50 AM

I have being using a non goto GM8 since 2010 for visual use with a 1200mm focal length 130mm refractor.  The setting circles work very well and are accurate in that with a 24mm panoptic and I think about 1.3 degree field of view I can almost always place a target in my field of view. For the occasional  misses  I simply use the hand controller to spiral out from my starting point. I am only keeping my finder scope on at the moment to keep more weight on the back of a front heavy triplet.

 

I will not comment on the other mounts you mention as I have no experience of them but I will say that a GM8 in use will be at least a three step operation, tripod, then head, then power supply, then telescope etc. In fact I think it is about the heaviest mount that I would want to regularly carry around.

 

The polar scope and I find easy to use but I cannot say how accurate it would be for astrophotography as I gain have no experience in this area. The mount has worked reliably for eight years now in the damp of the UK.

 

Hope this is of some help.

 

John


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#13 Spikey131

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Posted 07 December 2018 - 01:04 PM

Seems to me that “casual astrophotography” is an oxymoron, kinda like “casual formula car racing”.  Yeah, you can try it with the minivan, but......

 

Anyway considering you are mostly a visual observer, I would suggest one of the AZ/EQ mounts like the Skywatcher AZ/EQ5 because I think you would be happier with an AZ mount for your visual observing.


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#14 SteveGR

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Posted 07 December 2018 - 01:17 PM

If you are doing anything with AP, i'll just say that I bought an AVX for grab and go and entry level AP. As a visual mount, it is great, as an AP mount it has its limitations. If I had it to do over again, I would probably have gone with something with a proper bearing in each axis, like a Sirius or iOptron.

The AVX is capable of AP, but it's not as easy as other mounts may be.

Edited by SteveGR, 07 December 2018 - 01:21 PM.

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#15 WadeH237

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Posted 07 December 2018 - 01:37 PM

Seems to me that “casual astrophotography” is an oxymoron, kinda like “casual formula car racing”.  Yeah, you can try it with the minivan, but......

Not really.

 

Astrophotography is like anything else in that none of us are born knowing how to do it.  The learning curve and equipment requirements are both steep.  But once you've acquired the skills and gear that you need, then it can be done pretty easily.

 

As an example, we don't get many clear nights in my area, so I keep my system set up and covered all the time.  Last weekend, the forecast was showing 3 clear nights with no moon.  So on Monday morning, I went out and uncovered the system.

 

In this particular case, I found that there was a moisture problem with the telescope.  It's a really rare occurrence that I've only seen once before in the last 5 years or so, so I spent some time investigating (and started a thread on it).  It took a bit of time to get the scope dried out - but that delay is unrelated to imaging and an extremely unusual thing.

 

Anyway, for the astrophotography part, once I had the scope, mount and laptop powered up, I went back into the warm house and up to my office.  In my office, I connected to the outside laptop and configured an imaging plan for the night.  It took about 10 minutes.  Once I had the plan, I just hit "go".  The plan switched over night between 3 objects - and early evening object, a middle of the night object, an early morning object.

 

After that first night, I just reran the same plan each night.  That took a total of about 60 seconds of my time per night to kick off.  We ended up getting a 4th clear night last night, so I made a slight tweak to the plan to make the best use of the extra night and kicked it off.  That was about 5 minutes of work.

 

So this week, I have over 30 hours of imaging data, I've not lost a minute of sleep, and the system is now covered up again to wait for the next few clear nights.  That's pretty casual if you ask me - but it's built on top of many years of experience and significant investment.



#16 WyattDavis

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Posted 08 December 2018 - 07:34 AM

GM-8 and don't look back.  You'll be happy you put your money into a good mount.

It does look like a great piece of kit... Taking an even longer view, I can see a larger/longer refractor in my future as well. That actually makes me think a GM811 might be the best long-term solution for a high-quality GEM that can do both visual and AP. 

 

 

Seems to me that “casual astrophotography” is an oxymoron, kinda like “casual formula car racing”.  Yeah, you can try it with the minivan, but......

 

Anyway considering you are mostly a visual observer, I would suggest one of the AZ/EQ mounts like the Skywatcher AZ/EQ5 because I think you would be happier with an AZ mount for your visual observing.

 

I have taken a close look at the AZ/EQ5, too - it immediately caught my eye. My only hold-back there is that I already have a nice, heavyweight UA Doublestar mount with encoders on a CGEM mount as my "heavyweight" Alt-Az. Given that, I'm thinking it is probably going to be better to optimize on a GEM. 

 

I am getting that "casual AP" may be a bit of a misnomer. I got Jerry Lodriguss' Beginner's Guide to DSLR AP and have enjoyed going through it. He does make it clear that you can get started with very basic equipment but even this guide pretty quickly starts discussing multi-minute exposures and guiding...



#17 WyattDavis

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Posted 08 December 2018 - 07:42 AM

I have being using a non goto GM8 since 2010 for visual use with a 1200mm focal length 130mm refractor.  The setting circles work very well and are accurate in that with a 24mm panoptic and I think about 1.3 degree field of view I can almost always place a target in my field of view. For the occasional  misses  I simply use the hand controller to spiral out from my starting point. I am only keeping my finder scope on at the moment to keep more weight on the back of a front heavy triplet.

 

I will not comment on the other mounts you mention as I have no experience of them but I will say that a GM8 in use will be at least a three step operation, tripod, then head, then power supply, then telescope etc. In fact I think it is about the heaviest mount that I would want to regularly carry around.

 

The polar scope and I find easy to use but I cannot say how accurate it would be for astrophotography as I gain have no experience in this area. The mount has worked reliably for eight years now in the damp of the UK.

 

Hope this is of some help.

 

John

Very helpful John - thank you. The way you are using the GM8 is the way I would like to be able to use this next mount - in manual mode with setting circles plus an optical finder for additional reference. For my current scopes, it seems like the GM8 would be ample. I see you have a larger/longer refractor loaded. I have a 6" f/5 achomat that I would want to load up, and I could see doing a 6" f/8 achromat or possibly something like an AT152EDT F/8 in the future. Makes me wonder if a GM811 might not be even better. Any perspective on that given your experience with the GM8 in terms of mount stability - at least for visual?



#18 sg6

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Posted 08 December 2018 - 08:22 AM

For "casual AP" I suggest something in the line of the Skywatcher EQ5 - group here used to use that mount and a 72mm ED refractor and DSLR very successfully. Literally not 1 st up but about 6 or 7 of them.

 

Eventually people upgraded but it was a very nice fairly easy setup that gave good results.

 

You really need goto, cost is not much more and the minimum would be Eq mount and motors.

 

Skywatcher do an EQM 35 (I think) that is very simialr to the EQ5. WO did offer an AP kit with that mount and one of their scopes - may be worth investigating.

 

EQ5/EQM handle about 15lbs max, so it is a mount in that area. But goto is getting to be standard and not much alternative as motors are essential for AP in one form or another.


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#19 WadeH237

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Posted 08 December 2018 - 10:35 AM

It does look like a great piece of kit... Taking an even longer view, I can see a larger/longer refractor in my future as well. That actually makes me think a GM811 might be the best long-term solution for a high-quality GEM that can do both visual and AP.

If the GM811 fits the budget, and you want room to grow, it would be an excellent choice.

 

I've not used on myself, but I did get a good look at one in the field this past summer.  The build quality is excellent and it would be a fine performer for both visual and imaging.


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#20 JAC51

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Posted Yesterday, 04:55 AM

For visual the GM8 is fine for my scope which I've just weighed in as 10kg (22lb), This is tube, 3 tube rings, dovetail, finder 50mm and 2" diagonal left in place. I do though have the mount on a permanent pier now. Damping time is about 1s if I give the tube a firm tap but I use a JMI motor focus which eliminates most refocusing wobbles. When the wind is up the long tube does begin to oscillate at bit.

 

I will say though that if I was starting again I would be looking at the GM811 though I think it's only GOTO?

To have non goto digital drive it is I think the GM8 and the G11?

 

John



#21 WyattDavis

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Posted Yesterday, 06:19 AM

For visual the GM8 is fine for my scope which I've just weighed in as 10kg (22lb), This is tube, 3 tube rings, dovetail, finder 50mm and 2" diagonal left in place. I do though have the mount on a permanent pier now. Damping time is about 1s if I give the tube a firm tap but I use a JMI motor focus which eliminates most refocusing wobbles. When the wind is up the long tube does begin to oscillate at bit.

 

I will say though that if I was starting again I would be looking at the GM811 though I think it's only GOTO?

To have non goto digital drive it is I think the GM8 and the G11?

 

John

I think so - the GM811 only comes with the Gemini system that I can see. I automatically think "plan on 50% of the stated capacity of a mount" for real stability, but it seems like Losmandy owners are using them at higher ratios. Even so, the triplet 6" APO refractor I mentioned above would probably come in at more like 36 pounds if configured similarly to your scope + eyepiece and would be around 48" long - that seems like GM811 territory for sure. The GM811 looks to be around 6 pounds more than the GM8, and the G11 looks to be around 6 pounds more than the GM811. The G11 just seems to be completely overkill for me, so it may be worth going ahead with the GoTo system just to stay in the GM811.




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