Gap in my armoury.

[bomberbaz]

Recently it has become apparent I may have a gap in my scope armoury. The 80 and 102 fracs are great for most star related work, the 14" dob is a superb DSO hunter but the other day I ended up taking the big dob out to bag an asteroid when something a little smaller might have been more appropriate.

I am not rushing out to buy anything, I can cover my needs with what I have but just wondering what anyone else does and what thoughts are regarding this 100mm aperture to 350mm aperture as it is obviously is a big jump.  What do you guys do?

My head is saying I would need something in the 8" size if I went down this route as  storage is an issue, this would also steer me toward the compact designs. The stellalyra RC looks a lovely OTA at the 8".

Any thoughts or suggestions for me to mull over would be great. 

cheers all

Steve

 

[johninderby]

The StellaLyra 8” cassegrains are excellent scopes. The RC for DSOs and the CC for lunar / planetary.

[bomberbaz]

9 hours ago, johninderby said:

The StellaLyra 8” cassegrains are excellent scopes. The RC for DSOs and the CC for lunar / planetary.

I was thinking at F8 the RC are a bit of an all rounder.  

One issue I have only just noticed is the weight, at 8.5kg it isn't the lightest piece of kit unlike the edge hd which are 2kg lighter

[Nik271]

I've been tempted by the 8 inch edge HD in the past but considering its price bracket I think the StellaLyra RC is the better choice. 6kg vs 8kg is not a big difference, you still need a 10kg class mount to use them comfortably. There is now 8 inch carbon fibre RC which is a kilo lighter but a bit pricier. 

As far as I see the only slight disadvantage of the RC is that its collimation is tricker than a SCT. But there are many online manuals on collimating it nowadays so should not be a big deal if you store it in one location.

[johninderby]

The RC is a specialist astrophotography scope and can be tricky to collimate. The CC is the better visual scope and holds collimation very well and usually arrives well collimated.  The CC vs SCT is a fairer comparison although have found  the CC is sharper on axis than the regulari SCT with better contrast.

Edited January 21, 2022 by johninderby

[bomberbaz]

6 hours ago, johninderby said:

The RC is a specialist astrophotography scope and can be tricky to collimate. The CC is the better visual scope and holds collimation very well and usually arrives well collimated.  The CC vs SCT is a fairer comparison although have found  the CC is sharper on axis than the regulari SCT with better contrast.

Sorry John just to clarify, you feel the CC is sharper on axis than the SCT. Which do you feel has better contrast, CC or SCT?

[johninderby]

The CC just seems to have the edge in contrast.

Neil has a few threads on imaging the moon with the CC. He is very impressed with the scope.

 

[neil phillips]

Its been a while since i used a 8" meade SCT but i dont remember it being as good as this CC i think the top image speaks for itself. No matter who took it. collimation was tweaked again after this. As their was still a mild focuser tilt when these images were taken. If i was in the market for a 7 or 8" planetary lunar scope. the CC would be right up there on my list. 

Edited January 21, 2022 by neil phillips

[neil phillips]

A word of caution though. fairly narrow feild of view

[bomberbaz]

1 hour ago, neil phillips said:

A word of caution though. fairly narrow feild of view

That is what puts me off, why I thought about the RC at 8" as a good alrounder, although a 8" SCT wouldn't be a bad comprimise. 

[Captain Scarlet]

Just to add something to the mix there is a Skymax 180 in the classifieds at the moment (not mine) though at f/15+ It might not be your cup of tea

Magnus

[bomberbaz]

7 hours ago, Captain Scarlet said:

Just to add something to the mix there is a Skymax 180 in the classifieds at the moment (not mine) though at f/15+ It might not be your cup of tea

Magnus

You wouldn't happen to know if that OTA accepts a reducer would you, could be a compromise I would explore!

[Mr Spock]

What about an 8" Dob? They are almost grab and go. The 8" CC looks nice, but you need a good mount to carry it.

[Captain Scarlet]

3 minutes ago, bomberbaz said:

You wouldn't happen to know if that OTA accepts a reducer would you, could be a compromise I would explore!

I don’t know I’m afraid. I do know though that its image circle diameter is about 37mm, IIRC, from having used a DSLR to measure its true focal length. I’m not sure if that’s useful info.

M

[bomberbaz]

Just now, Captain Scarlet said:

I don’t know I’m afraid. I do know though that its image circle diameter is about 37mm, IIRC, from having used a DSLR to measure its true focal length. I’m not sure if that’s useful info.

M

haha, not really, all dutch to me. Just found an article which give the Antares 6.3 reducer would work. Takes it down to F9.45, I will think about this more. 

[bomberbaz]

I was looking around and spotted the Vixen VMC200, seems a nice OTA then I read about mirror recoating so it scared me off.

So far the best, albeit most expensive option would be an EDGE 8" but there must be others out there for consideration. The vixen would have been a worthy option but for the mirror issue. The Skymax 180 is ok but I would then potentially need a reducer, Antares 0.63 being available for this. There is still the stellalyra CC that would also accept the astro essentials 0.75 reducer. So much to think about. 

So I am going to mull over the options some more. Read up on specs of a few OTA and reviews that go with them.

Cheers all again.

[JeremyS]

I hear those Mewlon 210s give a passable view 🤔

[HollyHound]

45 minutes ago, JeremyS said:

I hear those Mewlon 210s give a passable view 🤔

Mewlon 180 is pretty decent too 👍

[bomberbaz]

12 hours ago, JeremyS said:

I hear those Mewlon 210s give a passable view 🤔

Lightweight, Japanese optics, great aperture, reducer available. Seems to tick the boxes. 

Thanks @JeremyS, I shall add it to the short list. 

[Captain Scarlet]

Another thing you need to consider is diffraction spikes. Maybe you don’t mind them, but all the open-tube options: Mewlon, CC, RC will show them. I’d have traded up my skymax 180 for a Mewlon otherwise.

M

[Captain Scarlet]

Ooo look an Antares reducer has just come up on the for sale section too … it’s fate! 🤣🤣

M

[bomberbaz]

12 hours ago, Captain Scarlet said:

Ooo look an Antares reducer has just come up on the for sale section too … it’s fate! 🤣🤣

M

Hahahaha, stop it, your making my finger itch. 

TBF I am really stuck on this. Cooling time issue against a Stellalyra CC, weight seemingly ok though.

Decision making time. 😉

[scarp15]

Similar to yourself, I run 85mm refractor, 200mm and 350mm dob, the 200 / 8" definitely fits in there.

[bomberbaz]

4 hours ago, scarp15 said:

Similar to yourself, I run 85mm refractor, 200mm and 350mm dob, the 200 / 8" definitely fits in there.

I am leaning towards the StellaLyra 8" CC with the possibility of adding an astro essentials reducer.

I have been checking the numbers and stats and the reducer doesn't seem to offer as much as I initially thought it might have done.

The 180 puts me off with cooling time, the F15 focal length and the smaller aperture. Shame really as it appears the views are superb but I can only go off my gut thoughts.

[johninderby]

Had a Skymax 180 before getting the CC8”. The CC is sharper on axis than the 180 with better contrast and resolution.