EAA with dobsonians - GOTO or EQ platform?

[Jonathan_Shields]

Hi all,

I have an 8 inch manual dob (Orion xt8) and have enjoyed observing planets and dsos and taking some simple planetary videos with a smartphone +Autostakkert/Registax etc. With DSOs i am to be honest underwhelmed by the views from my Bortle 6 back garden, but the lengthy capture sessions and expensive equipment needed for pure astrophotography hold limited appeal for me as a busy employee and husband/father. I have researched EAA and it seems appealing. I can get better views and if i really want capture and process an image for the downstairs toilet wall (although i accept ive then crossed the line into AP)

I am considering either

1) getting the Asterion Ecliptica light EQ platform £269 from First Light Optics and using my existing 8 inch dob. I then still need to star hop but i can do that if needed 

Or 2) Upgrading to a 10 inch goto dob...£1200 new or find a used one. I like the idea of not having to mess about finding stuff but will the goto track well enough for short EAA exposures?

and with either path getting a ZWOASI224 and a focal reducer. I realise the FOV limits me to smaller dsos but i like galaxies and globular clusters so i can live with that. A zwoasi294 would be better i know but 800 quid on top of the other stuff is somewhat steep right now.

Does anyone have any comments on the wisdom/ folly of these plans...should i just accept i need to save up for an EQ5 and an ED80 or is there a path with dobsonians?

[Cosmic Geoff]

I use for EAA both a 102mm achro refractor on an EQ-5 Synscan with an ASI224MC camera, and also a CPC800 with a f6.3 focal reducer and the ASI224MC camera.  If I had to pick just one I'd use the 102mm setup.  The  CPC800 setup (which gives much the same FOV you'd get with an 8" Newtonian) is more suited to small objects like planetary nebulae.  

I basically used kit I already had on hand (except for buying the focal reducer. )  Your choice is whether to aim for a widefield or narrowfield setup, and how much you want to spend on a camera. The ASI224MC is a planetary camera but works just fine for deep space except that the chip is small, hence narrow FOV.  I also strongly recommend that you aim for a full GoTo, which will let you easily find faint targets and use platesolve & resync to confirm you are aiming at the right place.  An equatorial mount is not necessary for the short exposures you are likely to be using, but the choice of alt-az GoTo mounts is limited, and the equatorial gives you the option of trying long exposures.

[Martin Meredith]

Hi Jonathan

Welcome to SGL!

Some people do a great job of EAA with Dobs on eq platforms. Check out Tiago Ferreira's YouTube channel for instance. He's active on CN (maybe here too) so would be able to answer questions about tracking. MikeJW uses a driven GOTO dob and produces excellent results with an Ultrastar camera. 

Finding objects could be tricky with a small FOV. Being able to platesolve frequently while finding would no doubt help. 

Its a direction I'm planning to go down myself soon, as it happens, but using a push-to 10" dob on an Asperion platform. My main use case will be visual as I now have access to darker skies. My rationalise is that a platform brings its own benefits for visual too e.g. easier to up the magnification or study details, and if it also works well for EAA that will be a bonus.

Do let us know how you get on.

Martin

 

 

[Jonathan_Shields]

7 hours ago, Cosmic Geoff said:

I use for EAA both a 102mm achro refractor on an EQ-5 Synscan with an ASI224MC camera, and also a CPC800 with a f6.3 focal reducer and the ASI224MC camera.  If I had to pick just one I'd use the 102mm setup.  The  CPC800 setup (which gives much the same FOV you'd get with an 8" Newtonian) is more suited to small objects like planetary nebulae.  

I basically used kit I already had on hand (except for buying the focal reducer. )  Your choice is whether to aim for a widefield or narrowfield setup, and how much you want to spend on a camera. The ASI224MC is a planetary camera but works just fine for deep space except that the chip is small, hence narrow FOV.  I also strongly recommend that you aim for a full GoTo, which will let you easily find faint targets and use platesolve & resync to confirm you are aiming at the right place.  An equatorial mount is not necessary for the short exposures you are likely to be using, but the choice of alt-az GoTo mounts is limited, and the equatorial gives you the option of trying long exposures.

Thank you Geoff. Its interesting that an achro refractor can get good results in EAA. Given the bargains out there for a Skywatcher 102 achro its tempting. I can see the CA might he a mild annoyance when looking at the moon etc but for eaa on dim galaxies im guessing its barely noticeable.

I can then source a used eq5 and sell the dob. As you say the mount then gives more scope for longer eaa exposures or maybe "real" AP if i ever feel the need.

Its an option worth considering.

[Jonathan_Shields]

7 hours ago, Martin Meredith said:

Hi Jonathan

Welcome to SGL!

Some people do a great job of EAA with Dobs on eq platforms. Check out Tiago Ferreira's YouTube channel for instance. He's active on CN (maybe here too) so would be able to answer questions about tracking. MikeJW uses a driven GOTO dob and produces excellent results with an Ultrastar camera. 

Finding objects could be tricky with a small FOV. Being able to platesolve frequently while finding would no doubt help. 

Its a direction I'm planning to go down myself soon, as it happens, but using a push-to 10" dob on an Asperion platform. My main use case will be visual as I now have access to darker skies. My rationalise is that a platform brings its own benefits for visual too e.g. easier to up the magnification or study details, and if it also works well for EAA that will be a bonus.

Do let us know how you get on.

Martin

 

 

Thanks Martin. I have been watching Tiagos videos with interest. Im quite tempted by the dob + eq platform route as i keep what i have and dont have to muck about selling stuff. I have a diy push to arrangement on my dob with a printed setting circle and an inclinometer which normally gets me within a degree or two although some nudging and finding is still needed.

The only issue with that is that unless i fancy attempting to build one(no ta!), the number of eq platforms available to purchase in the UK appears to be 1..  the Asterion Ecliptica Light and i cant find any reviews of it. If FLO are selling it im hopeful its not a complete lemon at least. 

Also finding objects will essentially be manual but maybe i can.live with that...the thrill of the hunt etc. Goto would be easier though.

Ill mull over the two options which have been helpfully supplied and see what appeals.

[oldfruit]

David Lukehurst has started making EQ platforms. I bought one from him for my large dob. The build quality is excellent.

[Cosmic Geoff]

18 minutes ago, Jonathan_Shields said:

Thank you Geoff. Its interesting that an achro refractor can get good results in EAA.

If you search in the EAA Reports you should find some images I made with the 102mm achro.

[Martin Meredith]

I started off my EEVA journey with a good quality 2nd hand achromat (StellaVue Nighthawk, 80mm f/6) and, to be frank, I found the CA really annoying very quickly. It was fine for the first few months as the EAA bug bit (everything looked good!), but once I started to look deeper the bloated stars that were present every time in every image were a real turn-off. I went for a Newt and never looked back. Honestly, unless you already have an achro to try out, I wouldn't recommend buying one specifically for EEVA.

[Jonathan_Shields]

On 26/06/2022 at 08:01, Martin Meredith said:

I started off my EEVA journey with a good quality 2nd hand achromat (StellaVue Nighthawk, 80mm f/6) and, to be frank, I found the CA really annoying very quickly. It was fine for the first few months as the EAA bug bit (everything looked good!), but once I started to look deeper the bloated stars that were present every time in every image were a real turn-off. I went for a Newt and never looked back. Honestly, unless you already have an achro to try out, I wouldn't recommend buying one specifically for EEVA.

Thanks. I am seeing some used 10" Skywatcher GoTo dobs for reasonable prices. I am thinking this is the way i will go. Kind of like Tiago but with goto instead of eq platform. Whilst i can star hop if pushed its  more time when i could be observing something.

[Mike JW]

Hi Johnathan,

Mike Wood here (Martin mentioned me), and as you will see in the EEVA thread I have used a variety of scopes for visual and then EEVA.

I used for awhile a 5" apo for EEVA and with my interest in going really deep I soon abandoned it in favour of my C9.25 that I had at the time. The C9.25 became C11 which reduced the time needed to collect the subs but my all time favourite is in fact my 15" Dob - quick at f4.5 (or at f3.5 when I use a reducer). The larger the scope then in theory the greater the resolution (but all the normal caveats apply), however the fov gets smaller so I loose out on wider fov that smaller scopes give. I have often thought that the ideal EEVA scope is somewhere in the 9" to 12" range and operating around the f4 mark. Thus I would concur with your thought of a 10" Dob.

Having said that a 10" is a good idea, look through what Martin M and Biil S achieve with their 8" Newtonians - really quite stunning. Their results sometimes out do my 15"!  Generally I can achieve better resolution and of course quicker but I have been fortunate to be able to own a large Dob.

GOTO is in my view the only way to go - manual is so slow and frustrating, especially when we have such limited clear spells. My early visual Dobs were manual and yes I enjoyed the star hopping but once I converted my current Dob I saw so much more visually and also using the EEVA approach. If time/money permitted I would run my 5" Apo on a separate mount and get the wide angle context for my Dob views.  (C9.25 with a hyperstar set up in an observatory works incredibly well but that is serious money and not where you are at).

Enjoy the journey.

Mike

PS. Chelmsford is my home town but I now live elsewhere.

 

[Jonathan_Shields]

18 hours ago, Mike JW said:

Hi Johnathan,

Mike Wood here (Martin mentioned me), and as you will see in the EEVA thread I have used a variety of scopes for visual and then EEVA.

I used for awhile a 5" apo for EEVA and with my interest in going really deep I soon abandoned it in favour of my C9.25 that I had at the time. The C9.25 became C11 which reduced the time needed to collect the subs but my all time favourite is in fact my 15" Dob - quick at f4.5 (or at f3.5 when I use a reducer). The larger the scope then in theory the greater the resolution (but all the normal caveats apply), however the fov gets smaller so I loose out on wider fov that smaller scopes give. I have often thought that the ideal EEVA scope is somewhere in the 9" to 12" range and operating around the f4 mark. Thus I would concur with your thought of a 10" Dob.

Having said that a 10" is a good idea, look through what Martin M and Biil S achieve with their 8" Newtonians - really quite stunning. Their results sometimes out do my 15"!  Generally I can achieve better resolution and of course quicker but I have been fortunate to be able to own a large Dob.

GOTO is in my view the only way to go - manual is so slow and frustrating, especially when we have such limited clear spells. My early visual Dobs were manual and yes I enjoyed the star hopping but once I converted my current Dob I saw so much more visually and also using the EEVA approach. If time/money permitted I would run my 5" Apo on a separate mount and get the wide angle context for my Dob views.  (C9.25 with a hyperstar set up in an observatory works incredibly well but that is serious money and not where you are at).

Enjoy the journey.

Mike

PS. Chelmsford is my home town but I now live elsewhere.

 

Thanks Mike i bet you have seen some sights with that 15"..a fair old unit as they say. I think a goto dob will be great for visual anyway as when you can only see mag 3 stars very faintly star hopping is a challenge. Chelmsford is Bortle 6 and they replaced the sodium streetlights with LED so CLS filters dont work so well. Plus everyone has so many security lights etc now the local stray light pollution is also an issue. With my 8 inch i can just see M1 and the leo triplet  and get a reasonable sense of m81/m82....hence the appeal of EEA to get decent views.

 

[lvan]

I use a goto mount, but i've often wondered about setting circles and a wixey and/or some form of mobile push-to, possibly even digital encoders, on a large dob with a tracking platform. I don't think you've got a lot to lose by trying. The tracking platform will have its uses.

Edited September 15, 2022 by lvan

[cajen2]

I think you'll find an Asterion EQ platform is now not in the running - they were made in the Ukraine and naturally supplies have run dry. I was lucky enough to get one of the last available.

[Guest]

On 15/09/2022 at 16:52, lvan said:

I use a goto mount, but i've often wondered about setting circles and a wixey and/or some form of mobile push-to, possibly even digital encoders, on a large dob with a tracking platform. I don't think you've got a lot to lose by trying. The tracking platform will have its uses.

I use setting circles and a wixey.  That is a solid combination and once you learn how to use them finding stuff is not an issue. 

[lvan]

On 17/09/2022 at 00:15, cajen2 said:

I think you'll find an Asterion EQ platform is now not in the running - they were made in the Ukraine and naturally supplies have run dry. I was lucky enough to get one of the last available.

Who knew?! Seems like most things of late. I had no idea they were such a manufacturing powerhouse!

[cajen2]

IIRC, it was just a couple of brothers making them, but they did a beautiful job:

[Jonathan_Shields]

Thats a shame. I should have bought one while they were going. I hope the brothers are OK and are able to take it up again.