GazOC

I bought a couple of these zooms off EBay for £42 each with the intention of using them as a pair for lunar binoviewing and as a single for quick looks.

The eyepieces are very light which is an advantage when you're putting all that extra kit on the back of a scope, the zoom action is smooth enough but with no click stops.

I used the eyepiece(s) in my ED120 and 127mm Mak/Cass, as expected the binoviewers needed a Barlow element screwed in to reach focus on the ED120 but worked fine without in the Mak. The views were sharp throughout the magnification range but showed some astigmatism towards the edges at the lower end in the ED120 at f7.5 but not the ~f12 Mak.  

The FOV on these zooms are narrower than the more expensive Hyperion zoom but it didn't feel too restrictive, overall I was impressed and think for £42 they are a bit of a bargain if you are realistic in your expectations 

8 minutes ago, johninderby said:

The StelaMira 80 is in the William Optics class of build quality, fit and finish and as good as if not better optical quality than any WO doublet which helps put the price into perspective. 

Aye! I'm certainly not knocking the optics or the fit and finish. It's just a fair bit of money for a 80mm visual scope, "too rich for my blood" as they say 

The other side to that is that on the occasions I've debated whether to buy gear that was slightly out of my price range I've never regretted it in the long run once my bank balance had recovered .

It's an amazing looking scope, Holly but a little pricey for me to consider. I'd definitely be interested in a cheaper "bare bones" version that had the same optical specs with less of the extra trimmings. Obviously that wouldn't fit in with the premium StellaMira badging but maybe it could be done under a different label?

Those diagrams show why the claim "I could see no false colour either in or out of focus" should be treated with extreme caution 

I guess you need to find some user reviews of the scope or a clone? At least then you'll know it performs as the specs suggest it should and it'll remove the gamble of taking it over the ED120.

Asuming the prices were similar, I think for the sake of an extra 5mm that isn't going to be noticeable at the eyepiece I'd probably go for the tried and tested (and lighter) ED120. 

If you can stretch to something a bit better than the AZ3 I'd recommend it. The mount can only track so far before it needs moving or re-setting and is pretty lightweight.

I never seen one in the flesh but I'd always imagined C9.25s to be smaller than that for some reason.

Aye! Having one Hyperion already would have made my choice easier too. 

Reviews seem to be good "for the price", Rob. I got the pair for just under £90, hopefully they'll be reasonable quality for lunar use 

I've just ordered a pair of Svbony 7-21 zooms for my 127mms Mak, I couldn't stretch to the Hyperions especially as I don't envisage using the zooms for anything but lunar views. Hopefully the IP distance will be OK as I've only binoviewed with small plossl EPs in the past 

12 minutes ago, johninderby said:

On the subject of the 180 actual,aperture.

https://www.cloudynights.com/topic/737321-sky-watcher-skymax-180-pro-mct-gold-tube-vs-black-tube-optical-performance/

There's not much there TBH, just a bloke saying it's 170mm ish.😀

I measured the primary, it's definitely 200mm. I did I bit of Googling afterwards and there is a difference of opinion on whether the testing methodology used to arrive at the effective aperture figure is valid, I can't really comment on the ins and outs of that as most of it went over my head but what I can definitely say is that the people who claim the effective aperture is 170mm because the primary is 180mm are wrong.

13 minutes ago, johninderby said:

The old blue tube version. The 127 hasn’t changed but the 150 and 180 were altered to correct the less than truthful actual aperture of the older versions.

 I have a gold 180mm Mak and the primary is 200mm, if Skywatcher wanted to push it they could have sold it a 8 inch Mak! I've seen people saying the mirror is 180mm and that gives a reduced effective aperture but that's not the case.  

**If** the scope for resigned at some point to add effective aperture  (and Skywatcher kept it secret!) then it wasn't because the primary is undersized as seems to be the reason that is most often quoted. 

Yep, it's a doddle. Just goes straight on 

It's easy to spend other people's money but my choice would definitely be to bite the bullet and buy the dedicated high power eyepieces you need 

There's only so much faffing around with parts you want to do on a cold night and the Tak would look a lot nicer without 100mm of plastic hanging off the back end 😉

The distance from the Barlow to the eyepiece gives the magnification by increasing the focal length of the system. The further away, the greater the magnication. So although you should get x2 before the diagonal, by putting the Barlow after the diagonal (nearer the eyepiece) you'll get a lot less.

This also moves the focal point differing amounts. With the Barlow before the diagonal the focal point will be further out than with the Barlow after the diagonal 

Cheers Peter, that's good enough for me 🤗

I'm looking at getting a couple of cheap Svbony 7-21mm zooms for casual lunar binoviewing. The reviews on the EP seem fine given the price tag but I'm a little concerned about getting the magnification of the 2 EPs correctly matched given that they apparently don't have click stops.

Has anyone got any experience of binoviewing with this EP  or a zoom that doesn't have click stops?

Cheers 

1 hour ago, Alkaid said:

It's not what you want to hear, but the scope is most likely written off.  As above, worth a check with home insurance, you may be able to cover it and buy a replacement.  Might be a while in this climate though.

Feel for you...nightmare...

If a repair IS feasible, then it might be better to have FLO send the scope back to Skywatcher for repair.  I'm not certain, but do SW try to match correctors with mirrors to give a 'good' optical fit??  

I don't *think* that's needed with Maks, the curves are simpler than a SCT,  the correctors should all be identical (I'm sceptical how much matching actually happens with SCTs TBH). 

It might be worth trying a classified ad for a corrector. It a long shot but somebody might have damaged a Mak mirror and have a spare. I have a spare 180mm Mak/Cass corrector due to a mirror damaged in transit so it's not beyond the realms of possibility.

That focusser does look the same as a Phenix 127mm f9.3 refractor I owned about 15-20 years ago.

Very good scope, only sold on when the Skywatcher EDs made it a bit redundant

Nice. Is the secondary adjustable or fixed?

5 hours ago, Splodger said:

If you on a really tight budget and just want finer control try The Poor Man’s Dual Speed Focuser - A Clothes Peg! Seriously, it works a treat. Just clip it onto the knob at 90° et voila! Fine adjustment at your fingertips. It works for me 😃

So it's not just me who does this! I've mentioned it a few times in threads over the years but no-one ever seems to follow up on it 🤣

I got this last with an ED120 + Barlow. First real attempt with the camera and lots to learn on the software/ settings side of things 

Great scopes, I have one permanently set up on an EQ 3/2 mount and just pick the whole thing up in one lift and plonk it in the garden if it's looking like a clear moonlit night 

Unless the number factors in the production schedule/ level at the cement factory 2 miles from my house then it's unlikely to be accurate