What EAA set up would you choose if you had to start again from scratch?

[Jimbo64]

I write this partly as a fun exercise, but mainly because I may face this dilemma.  My motorised 8" dob has lost all power and control and I face the prospect of having  to look for a new mount/ OTA combo to pair with my ASI585mc, which I've had for a few months now, but have hardly used it at all.

I think I'm still inclined to go with a goto 8" dob (https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-flextube-goto.html). I'm in the Bortle 7 part of the outskirts of Glasgow and had thought I'd be a mainly visual observer until I realised how little I can actually see. EAA seems the obvious answer to let me experience deep sky from home, particularly the small-fuzzies, so my initial thinking is to stick with the combo I haven't yet properly tried - the f6 dob and 585 would surely give me a great EAA experience, with the dob still just about portable enough to thrill through an eyepiece when I take it, as I occasionally do, to darker skies.

But rather than jump straight to that conclusion I'm wondering what other options for around the same £1,000 mark (or maybe a bit more) I should consider, which is when I thought that your views on what you would do now with the benefit of your insight of having tried and tested your own rigs would be a nice exercise for the imagination and one that might help me make up my mind and hopefully be a nice conversation piece here. I'd also get to tap in to a whole wad of experience, which is what I think that we all really like about this forum.

So, first option, would you now see an equatorial mount as essential - this seems to makes some sense given you have a camera, tracking is important and it could be paired that with a nice little apochromatic refractor, with lots of combinations/ options to choose from in the price range?

If that is the case, what would be the right proportionate spend on each - a £650 mount (https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eqm-35-pro-synscan-goto-modular-mount.html) and a £400 OTA (maybe something like: https://www.firstlightoptics.com/askar-telescopes/askar-fma180-f-4-5-astrograph-lens.html ). Or get a cheap mount https://www.firstlightoptics.com/sky-watcher-az-gti-wifi/sky-watcher-az-gti-wifi-alt-az-mount-tripod.html and a better (£800?) APO https://www.firstlightoptics.com/william-optics/william-optics-redcat-51-v1-5-apo-f49.html?

I hear good things about SCTs and Maksutovs, would one of them (on either alt-az or equatorial) be a good choice https://www.firstlightoptics.com/se-series/celestron-nexstar-6se.html for example?

Would a cheaper rig (the cheap mount/ cheap OTA above?), driven by something like an ASIAIR/ Raspberry pi be worth a punt?

If you like aperture surely a newtonian makes financial sense, one of these on an EQ mount could work a treat: https://www.firstlightoptics.com/reflectors/skywatcher-explorer-200p-heq5-pro.html ?

I'm sure that there are loads more variations on this theme, please let me have your thoughts and also maybe tell me why your experience would lead you to that conclusion. I'd be really interested in the thought process as well as the recommendations, particularly if it relates to what I should be choosing with the ASI585mc at the heart of my rig.

[Davesellars]

Personally, I wouldn't choose anything other than an EQ mount - it gives you more options for start to do AP as well as shorter exposure EAA which even this is restricted in only alt/az.  If you're going to be using relatively lightweight refractors, perhaps the EQ5 goto would be a good choice, although it's not that much more for the HEQ5...

I have found my 80ED quite capable so far - I'm yet to test my 102ED on the EQ5 mount for EAA - it should be fine though. I'm not sure I'd want to be using much less aperture than 80mm as it would be quite restrictive in the objects you could realistically view well.   A 4" ED refractor would be great for both EAA and visual observing.

Like you say...   there are many options!

 

[Martin Meredith]

Interesting question, and one that I've also been pondering on and off. I'm not sure if these thoughts are useful to you or not, but as you say it is a nice conversation piece, so this is my take.

Current setup: I've used an alt-az mounted 8" f4 (=800mm FL) Newt for the last 7 years for EEVA coupled with a small sensitive mono camera (Lodestar X2 mono or ASI 290MM mini) plus filterwheel to generate colour or explore narrowband. I haven't been tempted to go bigger in either aperture or camera size in all that time, because for me this setup allows me to capture almost all objects of interest at a decent resolution when seeing is good. I really like this setup and it has served me well for 1000s of observations, but either it is getting heavier or I am getting older...

If I were to start again from scratch, I might therefore consider going a little smaller in aperture. I wouldn't go smaller than a 6" Newt though, because I like to see detail in small galaxies and PNs, and I'd stay fast, because a 6" f/4 Newt is a pretty short and light scope that would mean I could dispense with my heavy EQ6-class mount.

An alternative that I've been thinking about recently is something completely different: an 8" (or 10") Starsense dob on an equatorial platform. This combination removes the need for a heavy driven mount altogether (and also simplifies the entire process since there is no time-wasting 2-star alignment, which I find tedious). Overall, this would be a lot lighter than my current setup. My only concern is whether the tracking is good enough for EEVA at this focal length. Someone needs to take the plunge and test it 🙂 This kind of scope would serve double duty as a visual scope, where the EQ platform would also help a lot.

As you can see, I like Newts, probably because my earlier EEVA experiences were plagued by chromatic aberration...

Martin

 

 

 

[RobertI]

I would personally stick with Newtonians or mirror scopes for EAA, although I know ED scopes are very capable. I have used an RC6 aggressively reduced to F4.5 to F5 and have had really nice results going very deep and nicely framing smaller galaxies with my Lodestar. Obviously collimation is needed but I don’t need do it very often in my RC6. I have been seriously considering a Skywatcher 150PDS F5 which wouldn’t need reducing or a 150P F4 and I think either would make great portable EAA scopes. I use a CG5 equatorial (EQ5 class) which seems to work fine for focal lengths of 700mm and can do up to a minute if needed (accepting the occasional trailing sub). 
 

I think a really nice setup would be a 150PDS on a Celestron AVX mount. You can use Celestron’s ‘Sky Align’ feature which allows aligning on any three bright stars - makes that part easier I think. It also provides support for polar alignment I believe. You also get an upgrade path to a Starsense for auto aligning in future. Plenty of folk use plate solving but I’m not there yet. I guess you’d need a coma corrector with your bigger chip?  

The Celestron NexStar 6SE is a good alternative for EAA with different strengths and weaknesses - no polar alignment hassle, but tracking not in the same league as the AVX I would say and scope is trickier to get reduced down to F5 effectively for your large chip.  

As an aside I have been experimenting with a 66mm F4.8 refractor on a Sky Prodigy altaz mount for quick wide field views, and to give me my EAA ‘fix’. It works for exposures of up to 15 seconds, and is good for widefield, but I wouldn’t call it a ‘serious’ EAA setup, especially the mount.

Edited October 25, 2022 by RobertI

[Cosmic Geoff]

I think having just one setup would be restrictive.  I have used:

102mm f5 Startravel achromat + ASI224MC +EQ-5 Synscan  for wider fields

CPC800 8"SCT (alt-az) + f6.3 reducer + ASI224MC for larger image scale.

Image rotation? I have some images taken with the CPC800 which show how live stacking compensates for the image rotation.

A larger chip (and more expensive) camera might be desirable, but could expose the deficiencies of the Startravel scope.

 

Edited October 26, 2022 by Cosmic Geoff

[Jimbo64]

Some good insights, thanks.

Dave, I agree the HEQ5 over EQ5 seems the right choice given the modest price difference, but I think it'd be hard to drop down from an 8" dob to a 4" refractor, I need to get to a star party to try some different rigs and spend some time at the pointy end of a refractor.

Martin, have you seen any of the YouTube videos by Tiago "Dobsonian Power"? He seems to get great results and enjoyment with no tracking issues with both 8" and 12" dobs on an eq platform, one example video is: https://www.youtube.com/watch?v=nLwkCaFbsxQ&t=56s 

And Rob, that AVX looks like a serious contender as a mount. Celestron also seem to do a great value bundle when adding a newt, so their packages look very competitively priced. But so does Skywatcher (and probably others).  I'd be new to eq mounts (but happy to learn) so it's hard to for me to compare, so any views on that choice would be great. I could easily over-engineer and future-proof this choice as the common advice seems to be to bite the bullet and just go for an EQ6-R-Pro - a 'proper serious' option.

I'm still drawn to my first choice, I loved my dob when it was working and I've added loads of nice little touches to it, but I fear that I might be suffering from some bias to lean towards what I've invested in and underdstand.  Is it just me or is this hobby likely to make you think that the gear you picked was a good choice, especially when there are so many options and everything seems to be decent quality and have its own merits?

 

[Mike JW]

Hi Jim

Aperture gives you resolution and quicker results (leaving aside the focal ratio discussion). In my experience with EAA stick with 8" of aperture or more. (As you see from my posts I have used a C9, a C11 and a 15" Dob).

Geoff is right to point out the idea of having two scopes (I used a 5" apo and a C9 at one point) - the smaller refractor gives those lovely wide field views which I miss now that I just have the 15" Dob.

A GOTO makes life easy (both visually and for EAA), so if you went down the EQ platform route then make sure the Dob is at least 'Push To'. My Dob is GOTO and not on a platform so it is of course Alt/Az and yes you get field rotation but the software (Jocular) deals with that. Also, I tend not to go beyond 15 sec subs (no need to with such a large aperture scope) so field rotation is not particularly significant.

As to the ideal aperture - matter of personal choice as to what you wish to observe. Personally, having used a variety of scopes I would not wish to go to less than a 12" Dob but as you will know from all the EAA reports an 8" scope gives a lifetime of objects to observe. Another factor is the ease of use. Mounts/scopes get heavier as you get older!!!!! The reason I can stick with my large scope is because it is always made up and simply rolls out of the garage by means of its wheelbarrow handles. I sold my C11/iOptron Mount - way too cumbersome and heavy to deal with but a great set up.

I also favour Newtonian scopes in the Dob format.

Decisions and yet more decisions and never a single correct answer!!!

Have fun

Mike

[Martin Meredith]

1 hour ago, Jimbo64 said:

Martin, have you seen any of the YouTube videos by Tiago "Dobsonian Power"? He seems to get great results and enjoyment with no tracking issues with both 8" and 12" dobs on an eq platform, one example video is: https://www.youtube.com/watch?v=nLwkCaFbsxQ&t=56s 

Yes, I've seen some of the early ones from Tiago. I suspect it would work if the platform is up to it. Unfortunately the Asterion platforms are currently unavailable.

I'm not sure why this option is not more popular. Taking for instance an 8" scope (say the Quattro that I have) and a the smallest suitable mount (heq5-pro), the total cost is around £1650 incl. power supply, and the weight is 37-40 kg depending on power supply. The 8" Starsense scope plus EQ platform is around £920 and the total weight is 25 kg. The main difference is that the former has goto and the latter has push to. I guess also the Starsense is not designed as an imaging scope, but it could be made to work especially with a small sensor camera.

Besides reduced weight and price, the pros of the EQ platform approach that I see are: easier and faster to setup/takedown/align for observing (saving perhaps 15 mins each session assuming one doesn't have an obsy); easier and more natural to use in visual mode; takes up less storage space. Cons: resetting the platform every hour. Any other pros and cons?

It is quite tempting. Perhaps it is time to sell the Quattro/Az-EQ6 combo...

 

[Mike JW]

David Lukehurst (GB) now makes equatorial platforms  David Lukehurst - Large Portable Dobsonian Do bson Dobsons Telescopes - Index (dobsonians.co.uk).

I ruled out platforms for my Dob (15") before I converted it to GOTO simply because I would have had to dismantle it to then reassemble it on the platform but for a small Dob (8"/10") I assume the scope could easily be lifted straight onto the platform. 

[Martin Meredith]

Thanks for the reminder about the David Lukehurst platforms. The website says they're prototypes, but I think it has said that for some years now. Even so, it would be interesting to hear from anyone with practical experience of them.

Weight and simplicity of setup is the main attraction for me. Simply plonk down a 5 kg platform, level it and set it pointing north (no need to actually see Polaris), then add the 10 kg Dob base, then the 10 kg Dob tube (for the 8" model), and get EEAV-ing

(of course, there is still mirror cooling to consider unless the scope is kept at ambient temp)

[Jimbo64]

Those platforms look more than capable - a bit 'home-made', but should do the trick nicely!

On 27/10/2022 at 11:19, Martin Meredith said:

Thanks for the reminder about the David Lukehurst platforms. The website says they're prototypes, but I think it has said that for some years now. Even so, it would be interesting to hear from anyone with practical experience of them.

Weight and simplicity of setup is the main attraction for me. Simply plonk down a 5 kg platform, level it and set it pointing north (no need to actually see Polaris), then add the 10 kg Dob base, then the 10 kg Dob tube (for the 8" model), and get EEAV-ing

(of course, there is still mirror cooling to consider unless the scope is kept at ambient temp)

 

[catburglar]

For me, the only significant limitation of alt-az mount for EAA is not field rotation per sub because as Mike said each sub is typically pretty short, but field rotation over the duration of the stack. 
 

The 585 sensor has the same 1:1.8 aspect ratio as my ASI290, and I think this format exacerbates the effect so that you lose more and more ‘stackable’ FoV as your stack length increases.

Obviously the impact varies depending on where in the sky you’re pointing and how big your FoV is to start … but I think with a 4:3 or 1:1 sensor I’d be happy to recommend alt-az, but with your sensor I think some sort of EQ will be preferred. 
 

The dob + EQ platform is probably the best of both, if you can live without goto…

[shirva]

Been  a while since I was last on.

What is the perfect rig for video/eaa astronomy,, think there are many factors  to the question,, what type of eaa,,   

Tried many  set up's since 2011,,

Back in the days of analogue cameras lol,,,

I've, had the skywatcher explorer 200pds on the heq5,, even done twin saddle and sw evostar ed80 on it.. 

Ideal if you have an observatory, unfortunately I don't,, and living 4 floors up in a flat,, ain't ideal for transportation. 

I've  tried a good few set up's from very portable  to what I thought would be ideal,, the sw azgti on a video tripod in eq mode  with  William zenithstar 61, sw 50ed guide scope,  zwo 178mc camera and zwo 120mm  camera connected to asiair,, yeah great set up but time  consuming and could be unpredictable at times. 

I have decided to go back to my eq3 Pro,,  sw WiFi adapter,, synscan app..

William zenithstar 61 and 50ed scope,, and connected to asiair,,

I'm doing live view wide field  and pretty happy  that this set up is pretty adaptable  to other variations,,like canon 600d  and byeos,, 

Really all depends on how you like  your eaa 

[RobertI]

2 hours ago, shirva said:

Been  a while since I was last on.

Welcome back sir. 👍

[Jimbo64]

I keep flip-flopping on what my next step will be.  I first thought that it was certainly going to be on an equatorial mount (HEQ5/ 8" Newtonian?), then my thinking moved to a more modest size system (eq3/ azgti? I totally empathise with @shirva) with decent enough goto and maybe an ASIAR control system would be it.

But I did love my 8" goto dob and the alt-az was more than good enough for my expectations of EAA, so I'm now on the cusp of just getting a bigger goto Dob.  My dilemma now is how big, anything over 12" seems too heavy and cumbersome, 10" would be better and more similar than my old rig, so 12" looks just about right.  

Dilemma, but I'm also building it backwards from having a ASI585mc as my starting point!

[shirva]

On 20/11/2022 at 22:04, RobertI said:

Welcome back sir. 👍

Cheers mate

[bosun21]

12 hours ago, Jimbo64 said:

I first thought that it was certainly going to be on an equatorial mount (HEQ5/ 8" Newtonian?), then my thinking moved to a more modest size system (eq3/ azgti? 

The driving force is to utilize what you have already got! That’s what you said to me.

[Jimbo64]

2 hours ago, bosun21 said:

The driving force is to utilize what you have already got! That’s what you said to me.

Yup, but my mount/ scope is busted, so I'm pretty much starting over!

[bosun21]

2 hours ago, Jimbo64 said:

Yup, but my mount/ scope is busted, so I'm pretty much starting over!

I know this, I am only pulling your leg!, how many years did you get out of your go to dobsonian before it packed up?

[Ratlet]

On the bright side, I'm pretty certain someone will buy your dob, even if the motors are packed in.  You can put that towards something else.

I wouldn't be too worried about moving to a smaller scope.  I tested my 130pds/Altair Astro 533c with 20 minute total integration on M27 and Stephens quintet and even just a stack and autostretch in siril gave great results.  I keep wanting to try livestacking but it's hard to give up the 130pds for sketching.

If only I had a dob for visual....

Edited November 23, 2022 by Ratlet

[Jimbo64]

4 hours ago, bosun21 said:

I know this, I am only pulling your leg!, how many years did you get out of your go to dobsonian before it packed up?

I only had 2 years use - bought it second hand and the previous owner had done the same, so I'm not at all sure how old the scope was, but it was a SynTrek model, so I'm guessing its at least a dozen years old.

[Jimbo64]

3 hours ago, Ratlet said:

On the bright side, I'm pretty certain someone will buy your dob, even if the motors are packed in.  You can put that towards something else.

I wouldn't be too worried about moving to a smaller scope.  I tested my 130pds/Altair Astro 533c with 20 minute total integration on M27 and Stephens quintet and even just a stack and autostretch in siril gave great results.  I keep wanting to try livestacking but it's hard to give up the 130pds for sketching.

If only I had a dob for visual....

I'll give this some thought, but it may well be that I seek a new home for a great piece of visual kit...

[PeterC65]

I have the Player One Uranus-C which is their equivalent of the ASI585 and have been testing it with each of my scopes, a TS-Optics 432 mm / 72mm APO refractor, Skymax 127 and Explorer 150PDS. I've pretty much decided that I will only use the camera with the refractor. The camera matches the scope very well, the refractor design makes for a very clean image, and I have no issues achieving focus. While the aperture is small the camera gain lets me observe way more detail than I've ever seen visually. The Mak is just too slow for the shorter exposure times that I need with EAA. The Explorer 150PDS is OK, but I don't like the diffraction and achieving focus is more of a problem.

I use an Alt-Az mount which I think is fine for EAA. For me EAA means a near to live experience so exposures no longer than 15 seconds. If you are likely to set the kit capturing, then go away for a bit while the image builds up then maybe an EQ mount would be better.

I also do visual observing and for that the Explorer 150PDS is my scope of choice unless I'm observing the Moon and Planets in which case I will use the Mak.

I've been around the houses many times on what kit to buy and my issue with a Dob is that the mount and OTA are one and the same. I prefer to be able to select different scopes depending on what I want to do and that's particularly important when switching between EAA and visual I think.

[Jimbo64]

Good points (as usual) Peter, and I totally get that having the choice of OTAs is a big benefit in having a versatile mount.

An idea has just struck me though, if I opt for the goto dob and at some point down the line I fancy adding a more wide-field option (possibly an apo like yours), could I not just plonk it (somehow?) on my newtonian and use my Dobsonian SynScan GoTo to do EAA through the apo?

[PeterC65]

7 minutes ago, Jimbo64 said:

An idea has just struck me though, if I opt for the goto dob and at some point down the line I fancy adding a more wide-field option (possibly an apo like yours), could I not just plonk it (somehow?) on my newtonian and use my Dobsonian SynScan GoTo to do EAA through the apo?

That's an interesting idea!

I've no experience with Dobs but I think you might get issues with balancing the combination and possibly with overloading the mount. It could be worth a try though, and the sort of APO that you need for widefield is likely to be lightweight (mine weight 2.2kg).

I think it is the widefield view that you might miss with a larger Dob, and from my experience, using a camera seems to result in a narrower field of view than is possible visually with any given scope.