New telescope advice for visual and DSO imaging

[salmja79]

Hi, wanted some advice from the community. I'm looking to upgrade my current set up (127 Mak) and have boiled it down to 3 telescopes.

A 10 in f4 Newtonian (stellalyra)

An 8 inch f4 Newtonian (stellalyra)

An 8 inch f8 RC (stellalyra)

An 8 inch f10 SCT (celestron)

I'm looking to do some backyards visual astronomy plus some DSO imaging. Currently leaning towards the 10 inch Newtonian but wanted to see if anyone has any experience with any of the above? Thanks in advance 

[happy-kat]

Hi, I think the first questions asked would be what mount are you intending to use for when DSO imaging, and what are your imaging expectations quick EAA or more detailed long exposure?

[Cosmic Geoff]

I have an 8" f10 SCT (CPC800) and I wouldn't swap it for any of the other scopes on your list.  I use it for planetary imaging, deep space imaging (with f6.3 reducer) and visual.  It has an excellent but heavy mount.

[Elp]

Also what tripod? Scopes with that sort of volume especially the Newtonians need very sturdy tripods, and possibly environmental shielding if you're imaging in open space.

Choice of scope also depends on the targets you wish to image, in what quality and with what camera sensor size.

[salmja79]

Thanks for the replies.  Looking to image both the  planets and some DSOs. Regarding the  mount, I was looking at some of those listed below due to budget. The 10 inch Newtonian is the heaviest scope weighing in at 15 Kgs for the OTA including rings etc. so thinking the NEQ6 for that scope but the Bresser Mount for the others and EQ-AL55i PRO fort he 8 inch SCT as the OTA weighs in at 6.5Kgs

• Sky-Watcher NEQ6 PRO
• Sky-Watcher HEQ5 PRO 
• Bresser Messier EXOS-2 EQ GOTO Mount And Tripod
• Sky-Watcher EQ-AL55i PRO Go-To Astronomy Mount

J

[Elp]

For future proofing might be wise to just get the neq6. You usually have to stick to 1/2 to 2/3 max payload weight of the max the mount can handle.

Planets need long focal length, DSOs not so much but it depends on the targets. You can do planets with Barlow lenses added prior to the camera but long FL scopes in the first place help, can even do it through the mak.

If you wish to do good quality DSO imaging more involved than EAA type, some sort of computer control and autoguiding is recommended. The longer focal length you image at the better everything needs to work together, it doesn't matter so much when imaging planets as the target signal is so strong, you can even get away with planet drift.

[salmja79]

thanks

[Ratlet]

Can't comment on the views other than to say that a 10" newtonian is great (on a dob), however I could not get on with using my 5" on an EQ mount.  They eyepiece just ends up everywhere, even worse than with a reflector.  I'd imagine this would be even worse with a 10".

[Clarkey]

17 hours ago, salmja79 said:

A 10 in f4 Newtonian (stellalyra)

An 8 inch f4 Newtonian (stellalyra)

An 8 inch f8 RC (stellalyra)

An 8 inch f10 SCT (celestron)

For these scopes I would definitely go for the NEQ6. As this is reduced now it is the same cost as the HEQ5 - so buy one whilst they are cheap!

FWIW, the F4 newtonians as supplied need a fair bit of work to get them up and running for imaging. (Mirror mask, spider, flocking, light leaks and possibly new focuser). They also need very accurate collimation. The RC8 is a great scope - but collimation can be a problem. I was lucky, mine is not too bad, but others have had major problems with collimation. Also, the RC scopes are not ideal for visual use.

Personally, if you want to use a scope for both imaging and visual, I would seriously consider F5 for a newt. Much easier to set up - in particular for imaging. F4 imaging scopes permanently set up in an observatory are OK, but they do take quite a bit of fettling to get right.

You could consider a refractor. Not as fast optically, but great for 'plug-and-play' use.

[happy-kat]

Is the gear going to be setup all the time or lugged in and out each time

[woldsman]

A few comments on the Newtonian option. There are a some things to think about before upgrading. Guiding gets tougher with bigger scopes. Neither mount comes with a Rowan belt mod as standard. I think the upgrade costs the same for both so if you are buying new, worth asking for it to be done. Rother Valley definitely sell the NEQ6 Pro with a Rowan belt modification and other suppliers may do too. I think anything bigger than a 6" Newtonian needs the NEQ6 or the HEQ6 Pro mount.  The Stella Lyra  8" f4  Newtonian comes with the very good  dual speed monorail focuser.  For dual use (visual & astrophotography), the focuser is critical because it needs to be able to take the weight of the camera & filters.  You'll need to factor in a coma corrector. Going up to 10" would be a huge leap. If the scope is not in an observatory, any wind could be unforgiving. You also have to be strong enough to lift and set the scope up every session. I think the 8" Stella Lyra OTA weights 8.4 Kg whereas the 10" weights 15.5  Kg! You  may also need  off axis guiding. Not all Newtonians have sufficient back focus though to permit OAG. Lastly, collimation at f4 needs to be precise and either a star test or electronic assistance or both could be needed.  You might want to consider an intermediate step - ie going from a 127 Mak to a 6" Newtonian which Stella Lyra offer with the same focuser.  I started with a refractor and added a 130mm and 150mm reflector as the bigger beasts looked very hard to tame!

 

Edited September 2 by woldsman

[Clarkey]

1 hour ago, woldsman said:

The Stella Lyra  8" f4  Newtonian comes with the very good  dual speed monorail focuser.

A few people have said the monorails are good. I had one on a TS scope and was not impressed - too much flex. Maybe I got a duffer.

[Les Ewan]

8 hours ago, Ratlet said:

Can't comment on the views other than to say that a 10" newtonian is great (on a dob), however I could not get on with using my 5" on an EQ mount.  They eyepiece just ends up everywhere, even worse than with a reflector.  I'd imagine this would be even worse with a 10".

I have a EQ6 Pro and I used it with a 12" f1500fl PDS Newt. The tube is a bit heavy for the mount but that was not my problem as it worked fine. The problem was the OTA was not only heavy and unwieldly to balance and the fact I'm well into the wrong side of 60 the eyepiece got into all sorts of awkward positions. Even the task of rotating the tube in the rings for a more comfortable position was a tiring and tedious rigremole.🤬

Back in the 60's some large amateur reflectors had rotating secondary heads but I suppose that would only add to the cost of mass produced modern units and the fact that driven GOTO Dobsonians  and single arm altaz mounts would make the such a thing redundant .

 

[Les Ewan]

20 hours ago, salmja79 said:

Hi, wanted some advice from the community. I'm looking to upgrade my current set up (127 Mak) and have boiled it down to 3 telescopes.

A 10 in f4 Newtonian (stellalyra)

An 8 inch f4 Newtonian (stellalyra)

An 8 inch f8 RC (stellalyra)

An 8 inch f10 SCT (celestron)

I'm looking to do some backyards visual astronomy plus some DSO imaging. Currently leaning towards the 10 inch Newtonian but wanted to see if anyone has any experience with any of the above? Thanks in advance 

Most of the Skywatcher reflectors with 2" focusers have a removeable  eyepiece tube on the 1.25" adapter which is fitted with a M45 thread in which it makes it possible with the proper camera ring adapter to fit a DSLR directly for prime focus imaging.

[salmja79]

6 hours ago, Clarkey said:

For these scopes I would definitely go for the NEQ6. As this is reduced now it is the same cost as the HEQ5 - so buy one whilst they are cheap!

FWIW, the F4 newtonians as supplied need a fair bit of work to get them up and running for imaging. (Mirror mask, spider, flocking, light leaks and possibly new focuser). They also need very accurate collimation. The RC8 is a great scope - but collimation can be a problem. I was lucky, mine is not too bad, but others have had major problems with collimation. Also, the RC scopes are not ideal for visual use.

Personally, if you want to use a scope for both imaging and visual, I would seriously consider F5 for a newt. Much easier to set up - in particular for imaging. F4 imaging scopes permanently set up in an observatory are OK, but they do take quite a bit of fettling to get right.

You could consider a refractor. Not as fast optically, but great for 'plug-and-play' use.

Brill, good tips. One QQ re the RC. I will have to set up and break down the rig each session (household with kids) so I like this because it's compact, lightweight and will do good DSO (collimation notwithstanding).Re it not being great for visual, can you elaborate? (I don;t think i'll be able to get hands on one anytime soon).

 

J

[Elp]

If you're going to do that I'd avoid a Newtonian as collimating every time will be a headache if you're rushing about, even if you can do it quickly.

My C6 holds collimation very well by the way and I setup and breakdown every time, but in such situations I just prefer refractor type optics.

[Xilman]

One point: the larger the f-ratio of a Newtonian, the easier it is to collimate. It also seems to hold collimation better.

The first real telescope I used was an 8" Newtonian at about f/6 --- it was almost 50 years ago and I don't think I ever found out the true value --- which was carted outdoors, set up, used, and then carted back indoors at each session. It hardly ever needed collimating though, to be fair, it was only ever used visually.

YMMV.

 

[Clarkey]

52 minutes ago, salmja79 said:

Re it not being great for visual, can you elaborate?

I believe the large central obstruction reduces contrast. (Although I do visual occasionally, I am really an imager). I did try mine once or twice for visual, but once set up I tend to leave imaging scopes alone.

As imaging scopes, I am a fan of the RC's. Once collimated they hold very well. I generally check the collimation on mine about once per year - but it is in an observatory.....

If was having one scope for both, I would look at the 4-5" refractors. I have a Starwave 115mm from Altair and it is excellent for imaging and visual. It is also really easy to set up using the standard StellaMira flattener, and because it all screws together there is no worries about alignment or back-focus. With a non-reducing flattener it has enough FL for galaxy imaging and with a reducer it can cover a larger field.

As an owner of most scopes (except SCT's), there is no real 'right answer'. Just depends how much you like fettling. Given your need to set up and breakdown each time you use it, I would keep it simple.

[salmja79]

Many thanks for all the advice.

 

J