Coronado or Lunt?

[petevasey]

Hi, guys,

Hopefully some of you have one of the following Hydrogen-alpha telescopes and might care to comment.  For many years now I thoroughly enjoyed my Solarview50  telescope which gave excellent results both visually and photographically.  Unfortunately it was damaged a while ago, and although returned to the Isle of Man on a couple of occasions is only marginally working - I no longer get the full range of tuning.   It appears that I need a new etalon assembly, but the wheels are grinding exceedingly slowly!

So with the Sun now very active I'm looking at alternatives, even though it would involve a considerable outlay.  I'm considering a Lunt 60mm and Coronado 70.  Both have similar focal lengths and working aperture.  The Coronado with 10 mm blocking filter at £2699 is considerably cheaper than the £3959 12mm blocked Lunt, but it may be that for photography (using an 8.9 mm diagonal sensor) I would need the 15mm blocking filter of the more expensive £3229 Coronado unit.  Although there are also Daystar offerings, having owned a Quark I was far from happy with the tuning system and interior Barlow which limited the field of view.

So over to you guys!  Which of the two main offerings gives the best view.  And also which is the easiest to tune?

Thanks in anticipation,  Peter.

[petevasey]

I should of course have included the Coronado 60mm dedicated scope (can't be used as an ordinary telescope).  My Solarview is dedicated anyway, and I have other scopes for 'ordinary' observing.   At £2198 decently affordable, although still the 10mm blocking filter size might be marginal for imaging.  My Solarview has a 20mm blocking filter!  Another feature which inclines me towards the Coronado offerings is the focal length - at 400 mm it's the same as my Solarview, which matches beautifully with my monochrome Altair GPCAM3 for a full Solar disc with room to spare.

But browsing, although this model is shown on the FLO website, I've a sneaky feeling it's discontinued.

Cheers,

Peter

Edited May 8, 2023 by petevasey
Minor text correction

[petevasey]

On 29/04/2023 at 17:02, petevasey said:

But browsing, although this model is shown on the FLO website, I've a sneaky feeling it's discontinued.

I've since found out that this IS still available, indeed FLO are expecting one shortly.  So if anyone has any opinions on either the Coronado or the Lunt units, PLEASE respond.  I expect the Coronado Solarview II and III single stack units perform similarly, the main difference with the III is the ability to use the 70mm aperture telescope without the filters - I'm not interested in that, and the etalon is still 60mm.  As far as the blocking filter size is concerned, although the diagonal of my GPCAM3 is 8.9 mm, the vertical size is 4.9 mm giving an image height of 42 arc-minutes at 400 mm focal length, plenty of room for the Solar disc, so a 10mm filter should be ok.

Cheers,

Peter

Edited May 8, 2023 by petevasey

[Highburymark]

The Coronado etalons are more variable than the Lunts, so it’s more of a gamble whether you’ll get a really good scope. That is reflected in the pricing, though Lunts have gone up significantly in recent years. 
The Solarview II scopes currently available are likely to be old stock - at least that’s what the good people on Solarchat seemed to think. If you can possibly try the Coronado before buying, that will at least take much of the risk out of the process. Otherwise, I’d definitely go for the Lunt.

[Ricochet]

I only have experience of using my 50mm Lunt so I can't give any direct comparison feedback but these are my thoughts.

Firstly, I notice that both the 60mm Lunt and 70mm Coronado  have "proper" 2 speed focusers. The 60mm Coronado has a sliding drawtube for rough focus and a helical fine focus. It might be fine but I'm not massively keen on the idea.

Secondly, the Solarmax 2 range use a sliding pin to tune the internal etalon. This looks like a much faster adjustment than twisting the pressure tuner knob on the Lunt scopes, so is it more difficult to fine tune? Additionally, Coronado have removed this in the upgrade to the Solarmax 3 range and now use external etalons mounted at the front of the tube. They say that this gives a better image than using an internal etalon. We can take it with a pinch of salt that the external Coronado is better than the internal Lunt as they are competitors, but it is safer to assume that it is true that the external Solarmax 3 design outperforms the internal Solarmax 2 design.

Thirdly, I have double stacked my 50mm Lunt. Since I bought the double stack unit I have never even considered observing without it. I would look at either buying a double stacked unit initially or consider how easy it will be to upgrade to a double stacked setup in future. The Lunt scope is a recent model and I think it is fairly safe to assume that the filter will be available as a future purchase should you wish to upgrade. If Mark is right that the Solarmax 2 scopes are old stock then might there be a problem buying a double stack filter if you want to upgrade a year down the line? If you go for the Solarmax 3 can you even buy the double stack filter separately? I don't see anyone selling them as separate units at this time. However, the double stacked 70mm Solarmax 3 is listed as having double stacked 60mm filters so perhaps it is the same unit for both scopes and it will continue to be available in future.

[Highburymark]

2 hours ago, Highburymark said:

The Solarview II scopes currently available are likely to be old stock - at least that’s what the good people on Solarchat seemed to think. If you can possibly try the Coronado before buying, that will at least take much of the risk out of the process. Otherwise, I’d definitely go for the Lunt.

Sorry - I meant Solarmax II

 

1 hour ago, Ricochet said:

 

Secondly, the Solarmax 2 range use a sliding pin to tune the internal etalon. This looks like a much faster adjustment than twisting the pressure tuner knob on the Lunt scopes, so is it more difficult to fine tune? Additionally, Coronado have removed this in the upgrade to the Solarmax 3 range and now use external etalons mounted at the front of the tube. They say that this gives a better image than using an internal etalon. We can take it with a pinch of salt that the external Coronado is better than the internal Lunt as they are competitors, but it is safer to assume that it is true that the external Solarmax 3 design outperforms the internal Solarmax 2 design.

Thirdly, I have double stacked my 50mm Lunt. Since I bought the double stack unit I have never even considered observing without it. I would look at either buying a double stacked unit initially or consider how easy it will be to upgrade to a double stacked setup in future. The Lunt scope is a recent model and I think it is fairly safe to assume that the filter will be available as a future purchase should you wish to upgrade. If Mark is right that the Solarmax 2 scopes are old stock then might there be a problem buying a double stack filter if you want to upgrade a year down the line? If you go for the Solarmax 3 can you even buy the double stack filter separately? I don't see anyone selling them as separate units at this time. However, the double stacked 70mm Solarmax 3 is listed as having double stacked 60mm filters so perhaps it is the same unit for both scopes and it will continue to be available in future.

All great points! 

 

On 29/04/2023 at 15:28, petevasey said:

Hi, guys,

Hopefully some of you have one of the following Hydrogen-alpha telescopes and might care to comment.  For many years now I thoroughly enjoyed my Solarview50  telescope which gave excellent results both visually and photographically.  Unfortunately it was damaged a while ago, and although returned to the Isle of Man on a couple of occasions is only marginally working - I no longer get the full range of tuning.   It appears that I need a new etalon assembly, but the wheels are grinding exceedingly slowly!

So with the Sun now very active I'm looking at alternatives, even though it would involve a considerable outlay.  I'm considering a Lunt 60mm and Coronado 70.  Both have similar focal lengths and working aperture.  The Coronado with 10 mm blocking filter at £2699 is considerably cheaper than the £3959 12mm blocked Lunt, but it may be that for photography (using an 8.9 mm diagonal sensor) I would need the 15mm blocking filter of the more expensive £3229 Coronado unit.  Although there are also Daystar offerings, having owned a Quark I was far from happy with the tuning system and interior Barlow which limited the field of view.

So over to you guys!  Which of the two main offerings gives the best view.  And also which is the easiest to tune?

Thanks in anticipation,  Peter.

Having come from a Solarscope 50 originally, you are probably used to great views. I wonder if a new Solarscope 50 or 60 might also be within your price range? Or could you trade in the old 50mm etalon? Just a thought.

[petevasey]

1 hour ago, Highburymark said:

Having come from a Solarscope 50 originally, you are probably used to great views. I wonder if a new Solarscope 50 or 60 might also be within your price range? Or could you trade in the old 50mm etalon? Just a thought.

Yes indeed - Until the problems started, the SV50 was head and shoulders above the competition.  And I keep hoping it will be again!  The etalon was damaged (decontacted) in January 2021 - yes two years ago!)  The scope had been on a side clamp on my mount for two days, then fell off - I can only think that changing temperatures had somehow loosened the clamp.  Back to Solarscope in the Isle of Man.  Helmut had major problems recontacting the etalon which when the individual plates were checked appeared to be ok.  But he had no success until he used new spacers in June 21.  Then it seemed ok.

BUT...  When adjusting the etalon, it would not tune to good definition until at the very limits either end of the adjustment travel instead of roughly in the middle of the travel which would allow me to tune it for either surface or prominences.  And even then was very marginal, certainly nowhere near the original visual performance although I could still get an almost acceptable image after processing.  With time it has got worse, has been back again twice for adjustments to the etalon carriage (a shim had shifted during transport on one occasion) but is still very limited.  Indeed I had to fit a spacer at the front end to allow the adjusting screw a bit more travel.  It's been like that since last Summer, but now with the Sun really getting cracking, I'm becoming very frustrated!

I understand Helmut has now assembled a completely new 50mm etalon which (quote) 'looks good', but hasn't yet tested it.  I can only live in (fading!) hope 😔  And I have no idea what it is going to cost!  But if it works in my scope, that's probably the best solution.  I might be able to claim something from insurance, although with the unit being almost 18 years old they might not look at me very kindly.  I'm not sure if the Solarview50 is still available commercially, but I've seen the occasional advert around £5000.   And at my age it's difficult to justify that level of expenditure for a relatively exotic item.  Anyway I'll give Helmut a few more weeks - the present weather patterns are far from conducive to Solar viewing never mind H-a testing, and then see where things stand.

Keep your fingers crossed for me, guys!

Cheers,

Peter.

[Nigella Bryant]

I personally can't fault the lunt. I've a 60mm double stack I bought second hand for £1950 four years ago. It even fell off my mount too last year with no damage except my racing heart rate. I definitely go for lunt. 

[petevasey]

Thank you, Nigella, what stunning images!  They certainly show the Lunt in a good light (pun intended!)  Does it use pressure tuning?  What camera did you use, and how many sub images are stacked? If indeed the result is from stacking.  You were very fortunate in acquiring such an excellent instrument at that price 😁  Many thanks for your interest.

Cheers,

Peter.

Edited May 8, 2023 by petevasey

[Nigella Bryant]

45 minutes ago, petevasey said:

Thank you, Nigella, what stunning images!  They certainly show the Lunt in a good light (pun intended!)  Does it use pressure tuning?  What camera did you use, and how many sub images are stacked? If indeed the result is from stacking.  You were very fortunate in acquiring such an excellent instrument at that price 😁  Many thanks for your interest.

Cheers,

Peter.

Thanks Peter, it's pressure tuned. Full disks are 40% stack of 1000 frames. I use the Zwo Asi 178mm and add false colour in photoshop. As I'm only imaging in one wavelength it's easy to add the false colour. Here's some attached without false colour added. 

[petevasey]

Thanks, Nigella.  Yes, that's how I process my H-a images. When my scope was working at its best I got similar fine detail, but not such contrasty filaments, probably because the SV50 is a single etalon. 

Cheers,

Peter.

[Guest]

You know, it seems like i read somewhere that the new ZWO robot telescope.... StarSee or whatever its called ... Can be used for solar observation.  Dont know if that is something that might interest you but it is an option 

[Sunshine]

Though I cannot speak for the Coronado scopes mentioned in your post, I can say I have owned a PST and am on my second Lunt 60 in 5 years and If I were to speak from a customer care and satisfaction POV I would say Lunt is on another level in this regard. When I had my PST I tried contacting Meade a million times with questions about maintenance and replacement parts but my attempts at speaking with someone who cared in the least bit were futile. Lunt on the other hand were the very definition of customer service, how much is that worth? I can't imagine chasing a company down for assistance with a scope which costs what they cost ( a lot) I would be furious. This alone would deter me from any meade product again, solar or night. Don't get me started on night observing Meade products, I have had a few and it was the same story every time, on one occasion it took me to speak to no less than six different people before my simple question was answered, unreal.

Edited May 9, 2023 by Sunshine

[Merlin]

I double-stacked a LS50f to a PST and the duo get on very well.

[michael.h.f.wilkinson]

I have a Coronado SolarMax-II 60mm with a double-stack unit. Visually it is a nice instrument, although with the double-stack unit in place the image is rather dark. I do not like the central obstruction the scope has, in particular at lower powers. I have also struggled imaging with it, not so much at prime focus, but with any tele-centric lens added for higher resolution, where I got some seriously weird internal reflections. Might be different on newer scope like the SolarMax-III 70 (it still has the central obstruction, however). Below are comparison images with the Lunt LS35THa, Coronado SolarMax-II 60mm single stack, and APM 80mm F/6, with Baader TZ-4 4x tele-centric, Beloptik Tri-Band ERF, Solar Spectrum 0.3 Å H-alpha filter, and ASI174MM.

(click on image for full resolution)

[petevasey]

Thanks again folks - lots to think about!  A hazy but reasonably clear sky today gave me an opportunity to try my ailing SV50 again.  As you can see the haze produced a halo around the brighter prominence exposures - they were longer anyway than those used for the overlaid disc.  The partial frame is from a pre damage image taken in 2016.  I think you'll agree that there is better definition and contrast.  There again, maybe the haziness reduced the contrast in today's image.  Perhaps I should try again under better conditions.  But the telescope still works.  Just.  A lot will depend on whether Solarscope have got an etalon which will tune better, and not cost the earth.  Time will tell.

Cheers,

Peter.

 

Edited May 9, 2023 by petevasey
Improved image

[Highburymark]

Have you tried asking for the views of members on Solarchat Pete? Obviously the etalon is still contacted. Would be very interesting to see how it performed double stacked. 

[petevasey]

37 minutes ago, Highburymark said:

Have you tried asking for the views of members on Solarchat Pete? Obviously the etalon is still contacted. Would be very interesting to see how it performed double stacked. 

I hadn't been aware of Solarchat, though how that can be I don't know 😉  Anyway, I have now joined, thanks for the suggestion, and I'll have a good browse before posting anything, there might be enough opinions already there!

Cheers,

Peter

[petevasey]

Been a while since I started this thread, and I'm still hovering on the brink.   My Solarview50 still isn't working as I would like.   Although I got a half reasonable image on November 24th, it's back to being very marginal, some days better than others.  With it being on the very limit of adjustment, perhaps it is affected by both temperature and atmospheric pressure.   I did get in touch with Solarchat, and the general consensus was that the Solarview50 is indeed head and shoulders above the competition.   Anyway it's going back to the IOM in January for a final attempt to get it up to scratch, at least a rebuild of the existing etalon or possibly even a complete replacement etalon although I have some trepidation about what that would cost!

So fingers firmly crossed.  But if it ends up in the recycling bin (shock horror!!)  I think the Lunt double stack will be the way to go, particularly after seeing Nigella's superb images earlier in this thread.

Merry Christmas to all

Cheers,  Peter

Edited December 12, 2023 by petevasey

[Nigella Bryant]

Sorry you've still not got any satisfaction from your scope. Some more tempting image's from my 60mm DS lunt from November 2023.

[petevasey]

Thanks, Nigella.

Tempting indeed!  Just need a lottery win 😉

Cheers, Peter

[Carbon Brush]

Another satisfied user of a 60mm Lunt, pressure tuned. The scope developed the foggy blue filter a few years back and a replacement (FOC) was in the post in a few days.

However.....
With any Ha scope that you buy, there is a big variation in etalon performance from one scope to the next.
You may get a good, or less than good, example. It depends on what the manufacturer deems satisfactory for an amateur, or holds back for a reasearch scope costing £££££
I remember in early PST years reading about someone setting up outside an astro shop and choosing from 3 that were in stock.
More recently there have been reports of wide performance variation in Daystar quarks & scopes.
I remember asking (2019?) at an exhibition about a quark Ha eyepiece costing much more than a solarscout complete scope and the retailer had no answer.

If you buy a new Lunt and it isn't 'right' and you get enough good weather try it in a reasonable time, it can go back.
The nice thing is that you have another scope for a side by side.

David.

[Nigella Bryant]

3 hours ago, petevasey said:

Thanks, Nigella.

Tempting indeed!  Just need a lottery win 😉

Cheers, Peter

I know, they're nutty price new.

[Highburymark]

8 hours ago, petevasey said:

Been a while since I started this thread, and I'm still hovering on the brink.   My Solarview50 still isn't working as I would like.   Although I got a half reasonable image on November 24th, it's back to being very marginal, some days better than others.  With it being on the very limit of adjustment, perhaps it is affected by both temperature and atmospheric pressure.   I did get in touch with Solarchat, and the general consensus was that the Solarview50 is indeed head and shoulders above the competition.   Anyway it's going back to the IOM in January for a final attempt to get it up to scratch, at least a rebuild of the existing etalon or possibly even a complete replacement etalon although I have some trepidation about what that would cost!

So fingers firmly crossed.  But if it ends up in the recycling bin (shock horror!!)  I think the Lunt double stack will be the way to go, particularly after seeing Nigella's superb images earlier in this thread.

Merry Christmas to all

Cheers,  Peter

Sorry to hear the SV50 still isn’t fully performing. If you do go ahead and invest in a new set up, it might be worth asking Helmut for Solarscope new prices. In my experience they were very competitive with Lunt. I bought double stacked 70mm filters (full aperture, external) for the same price as a double stacked Lunt 80 - which features  smaller (50mm I think) internal etalons. As Nigella says, Lunt prices are silly. I wonder if a SV60 DS might be not much more than a Lunt 60DS?

[petevasey]

4 hours ago, Highburymark said:

Sorry to hear the SV50 still isn’t fully performing. If you do go ahead and invest in a new set up, it might be worth asking Helmut for Solarscope new prices. In my experience they were very competitive with Lunt. I bought double stacked 70mm filters (full aperture, external) for the same price as a double stacked Lunt 80 - which features  smaller (50mm I think) internal etalons. As Nigella says, Lunt prices are silly. I wonder if a SV60 DS might be not much more than a Lunt 60DS?

Nice thought - I have a TS65 quad - 65 mm objective, excellent optics, 420mm fl.  Although of course it is a Petzval setup, I believe that enough of the heat is removed by the front filter that the flattener lens would not be damaged.  So a Solarscope 60mm filter set would be very desirable, a double stack even more so.  BUT the prices are terrifying!  Single etalon,  double stack.  I don't know what the final cost of the repair to my SV50 will be, but I'm sure it will be way below those prices.  No doubt APM have a substantial mark up.  I daresay if I bought direct from Helmut I'd get a more competitive price.  But that would be for consideration if all else fails.

As you can see from the main page even the SV50 costs well over £5000 new from APM, 3 1/2 times the price of a basic Lunt 50mm!

Cheers,

Peter

Edited December 12, 2023 by petevasey