Getting to know the Lunt LS60

[Highburymark]

Thought I'd jot down some notes about my new Lunt LS60 as I think my experience might be useful to anyone else who may be thinking of buying a new ha solar scope.

I previously had an LS50 - a terrific little performer - but I wanted something a bit bigger that could offer more magnification while maintaining detail and resolution. I considered a Daystar Quark, but I'm afraid there were just too many stories of poor reliability and questionable customer service. However, moving up to an LS60 is a big commitment - particularly if you go for  a 60mm double stack filter as I did. But living in the centre of London means that I do more solar than night time observing, so I sold a lot of other kit, including the LS50, and raised enough cash for the pressure tuned version with the B1200 blocking filter. The best deals on offer were from Astrograph (the scope) and Tring (the filter) - both well below the rrp at other retailers. So I swooped.

The scope arrived first - so I was not a little excited to see how it performed in single stack mode - using Pentax XF zoom and TV plossls.  That first week I had three separate sessions - all of them hugely disappointing. First of all, the pressure tuner itself had to be screwed almost all the way in before any change in the sun's disc was noticeable. By this I mean the PT had to be tightened until it was well beyond the last exposed brass thread. This made it very difficult to keep the image in the eyepiece while adjusting the pressure. At this point I could see some small proms - but the surface was very washed out. The fourth session was a little better after I had greased the o-rings in the tuner. This time there were hints of mottling and possibly a small filament - but again the PT had to be tightened to the end of its range to see anything. There appeared to be no real sweet spot when moving the sun's image around the fov either. 

Not impressed.

Then the double stack filter arrived. My LS50 was transformed by double stacking, and I was praying that that this scope would be the same. Out into the garden. Nice clear day. As I cranked up the pressure..... my heart sank a little. A blank disc apart from a small sunspot. The sort of image attainable with a £20 sheet of Baader solar film. Perhaps I had a damaged etalon? I regreased the pt. Acclimatised my eyes. Threw a towel over my head. On with the eyepatch. Tuned and clocked the DS filter. Perfected focus. Adjusted the piston. Now I noticed better mottling - a few small but nice proms. Pushed up the magnification with the Pentax zoom - and was surprised that helped deliver more contrast too.

Now I was starting to have a bit of fun. Right up to 6.5mm, the proms were looking very nice indeed. Then I thought I'd check 'Gong' - and saw the most featureless sun i think I've ever seen. So I ended the session more hopeful that I was making progress. If you'd asked me then whether the views I'd seen were of the quaility I'd expect from a telescope costing as much as this had, then the answer would have been an emphatic no. But at least we were heading in the right direction.

Ahead of the next session, I refitted and regreased the PT o-rings, and attached a Baader Steeltrack focuser in place of the rather poor stock GSO unit, which allowed me to reach focus with my binoviewer. I also experiemented much more with the double stack filter - achieving more tilt than I had previously. And I made sure that the next observation was earlier in the morning for better seeing. Frankly, the single stack views were still very disappointing. Yes there was slightly better detail - mainly because of the binoviewer - with 15mm TV plossls. But not of the order I was hoping for. Then I attached the DS. Adjusted the DS tuner so the sun 'shadows' - which are a feature of all external DS filters - were only just out of view (so the background sky was redder than previous views), and was rewarded with a wonderful sight - the best proms I have ever seen - breathtaking detail with both the Pentax at 6.5mm and the 15mm TV plossls In the binoviewer. I pushed up the PT further, moved the image around the fov. And there were the lovely snaking filaments I'd been waiting to see ever since first light, beautifully contrasted in three dimensions against the orange peel surface. Today I've been out again - trying out a pair of 25mm Fujiyama orthos in the bino - and have enjoyed even better results, particularly following a great arching prom on the limb. 

So - when I bought this scope I knew there would be a learning curve, but I also thought my experience with the ls50 would mean I'd be up and running quickly. In fact it has taken 5-6 weeks to get to the stage I am now. Every pressure tuned Lunt is different - and I'm glad I've been patient with this one, working out its foibles and quirks. I'm still not happy about the PT travel or the views in single stack, but double stacked it's absolutely delivering. I'm going to try changing the o-rings for another pair with a slightly thicker cross section to see if it makes any difference to the PT, or to single stack views. But otherwise I now have the solar scope I wished for.

[John]

This is very timely for me Mark. Thanks for posting this report

[Highburymark]

Pleasure John - look forward to hearing about your plans too 

[garryblueboy]

Hi Mark I to have similar results as you having moved from the 50 double stack I too wasn't blown away by the 60 single and my tuner is tuned in quite near the end of travel but gave some reasonable views but when I put the 75ls stack which acts as a 60 on the Lunt 60 it was stunning and last week in single on my Tak bino it was the best I've seen glad your getting there I was lucky I picked up one of the Lunts with a feather touch for a great price , also took a punt on ls75 filter which proved to be a massive bargain 

[David Smith]

Interesting write up Mark. Would you consider that the additional 10mm of aperture (at a premium of what must be £2000) is good value?

[GavStar]

These pressure tuned scopes do seem tricky to get working ok. For this reason I plumped for the old tech tilt tuned earlier this year and in single stack mode my Lunt 60mm gives great visual views imo. I'd like to get it side by side with a pressure tuned version one day just to be able to directly compare. But I'm happy to stick with my tilt tuned for now.

[Highburymark]

1 hour ago, garryblueboy said:

Hi Mark I to have similar results as you having moved from the 50 double stack I too wasn't blown away by the 60 single and my tuner is tuned in quite near the end of travel but gave some reasonable views but when I put the 75ls stack which acts as a 60 on the Lunt 60 it was stunning and last week in single on my Tak bino it was the best I've seen glad your getting there I was lucky I picked up one of the Lunts with a feather touch for a great price , also took a punt on ls75 filter which proved to be a massive bargain 

Very interesting Garry - I've seen pics of your Tak with the 75mm Lunt filter. Looks fantastic. Have wondered about the potential for attaching my 60mm Lunt DS filter to my Tak - or even my 80ED. but haven't looked into whether it's possible, or where to source an adapter. So do you prefer single stack Tak with Lunt 75mm to double stacked LS60?

Thanks for your post - always learning new things about solar ha.....

[garryblueboy]

It's a tough choice between the single 75 or double 60 I'm lucky I can have both you should be able to get an adapter made up try Brian at astroparts1@btinternet.com he does stuff like that he was going to do me an adapter to mount a coranado 60 to my Lunt until I got the ls75 I would def say the single 75 is better than the 60 and conditions allowing some fantastic detail is seen I've not tried double stacked bino yet so that may be a pleasant surprise 

[Highburymark]

1 hour ago, David Smith said:

Interesting write up Mark. Would you consider that the additional 10mm of aperture (at a premium of what must be £2000) is good value?

I don't think I've seen the full potential of the scope yet David. Even so it's difficult to justify such a large premium for a relatively small step up in aperture. But I probably do three times as much solar as night time observing, and worked out that the value of my LS50 DS and various other gear I was not using regularly pretty much bought me the 60. I've been very impressed by the step up in what the extra 10mm delivers. I should also add that it has allowed me to binoview ha solar for the first time, and use my favourite Pentax zoom which would not reach focus in the LS50. So for me, the trade up has been worth it. But getting addicted to solar is not cheap.....

 

[Highburymark]

43 minutes ago, GavStar said:

These pressure tuned scopes do seem tricky to get working ok. For this reason I plumped for the old tech tilt tuned earlier this year and in single stack mode my Lunt 60mm gives great visual views imo. I'd like to get it side by side with a pressure tuned version one day just to be able to directly compare. But I'm happy to stick with my tilt tuned for now.

Sounds like you landed a great scope Gavin. There are lots of different claims for pressure tuning over tilt (no banding/wider sweet spot/ability to see 3D effect more on filaments/better adaptation to individual locations and environments etc). But I remember Peter Drew saying best view he'd seen through a Lunt was tilt tuned. Thing is that all ha scopes are different - difficult to generalise

[Highburymark]

22 minutes ago, garryblueboy said:

It's a tough choice between the single 75 or double 60 I'm lucky I can have both you should be able to get an adapter made up try Brian at astroparts1@btinternet.com he does stuff like that he was going to do me an adapter to mount a coranado 60 to my Lunt until I got the ls75 I would def say the single 75 is better than the 60 and conditions allowing some fantastic detail is seen I've not tried double stacked bino yet so that may be a pleasant surprise 

Thanks v much for the tip. And from my limited experience so far, double stacked binoviewing is just amazing. One surprising aspect I discovered is that I don't need to cover my head or make any attempt to block out light to see detailed features when binoviewing the sun. Didn't expect that

[David Smith]

23 minutes ago, Highburymark said:

I don't think I've seen the full potential of the scope yet David. Even so it's difficult to justify such a large premium for a relatively small step up in aperture. But I probably do three times as much solar as night time observing, and worked out that the value of my LS50 DS and various other gear I was not using regularly pretty much bought me the 60. I've been very impressed by the step up in what the extra 10mm delivers. I should also add that it has allowed me to binoview ha solar for the first time, and use my favourite Pentax zoom which would not reach focus in the LS50. So for me, the trade up has been worth it. But getting addicted to solar is not cheap.....

 

Mark, appreciate the candid response. I am trying to resist the urge to upgrade my H Alpha setup but still considering options! If I have to spend £4000 to get quality images then the discussion will be academic anyway.

Enjoy your new setup

[niallk]

Hi Mark,

Very honest review - I've been keen to hear your experience. I hope that things are coming together, and it sounds like double stacked with the BV is delivering great results. Beautiful setup!!

It was looking through a LS 60mm double stacked with a 50mm etalon with binoviewers that hooked me.

I've come across this - and am holding out some hope that it might allow me to BV with my LS50.  Two lens elements screw into different parts of the optical train:

-Niall

[alanjgreen]

I think that binoviewing a double stack ls50 will give a very dim image. Probably a step too far. 

My experience with binoviewing the double stack ls60 (with 60mm DS) is that it is very good. I never use single eye anymore for solar.

i also recommend people with ls60 scopes and  ds60 double stacks look into the m90 rotators that allow you to turn the DS unit while looking through the eyepiece- more detail can suddenly appear as you rotate the front DS unit based on the conditions.

its a case of matching both etalons to the conditions to tease out the extra filament or too.

https://www.teleskop-express.de/shop/product_info.php/info/p4295_TS-Optics-360--Rotation-with-M90-thread.html

Edited October 16, 2017 by alanjgreen

[Highburymark]

3 hours ago, niallk said:

Hi Mark,

Very honest review - I've been keen to hear your experience. I hope that things are coming together, and it sounds like double stacked with the BV is delivering great results. Beautiful setup!!

It was looking through a LS 60mm double stacked with a 50mm etalon with binoviewers that hooked me.

I've come across this - and am holding out some hope that it might allow me to BV with my LS50.  Two lens elements screw into different parts of the optical train:

-Niall

Thanks Niall - I've certainly read reports from LS50 owners in the US using Siebert OCAs to reach focus with binoviewers. You'd need the B600 blocking filter - I tried binoviewing with a B400 with no joy. The good thing about the Siebert OCAs is that they keep magnification down. They're not cheap, but if they allow binos to be used then that investment may be justified. I understand that they are happy to discuss individual requirements over the phone if you need more information. Lack of brightness may be a factor - if you trawl the Cloudy Nights and Solarchat forums you should be able to find out the feasibility of double stacking and binoviewing with the LS50.

[niallk]

41 minutes ago, alanjgreen said:

I think that binoviewing a double stack ls50 will give a very dim image. Probably a step too far. 

My experience with binoviewing the double stack ls60 (with 60mm DS) is that it is very good. I never use single eye anymore for solar.

i also recommend people with ls60 scopes and  ds60 double stacks look into the m90 rotators that allow you to turn the DS unit while looking through the eyepiece- more detail can suddenly appear as you rotate the front DS unit based on the conditions.

its a case of matching both etalons to the conditions to tease out the extra filament or too.

https://www.teleskop-express.de/shop/product_info.php/info/p4295_TS-Optics-360--Rotation-with-M90-thread.html

When I viewed through the LS 60 DS + BV, the front mounted etalon was 50mm aperture ... and the views were stunning! This is what is giving me (misguided?) hope

Anyways don't wish to derail the thread.

[niallk]

10 minutes ago, Highburymark said:

Thanks Niall - I've certainly read reports from LS50 owners in the US using Siebert OCAs to reach focus with binoviewers. You'd need the B600 blocking filter - I tried binoviewing with a B400 with no joy. The good thing about the Siebert OCAs is that they keep magnification down. They're not cheap, but if they allow binos to be used then that investment may be justified. I understand that they are happy to discuss individual requirements over the phone if you need more information. Lack of brightness may be a factor - if you trawl the Cloudy Nights and Solarchat forums you should be able to find out the feasibility of double stacking and binoviewing with the LS50.

That sounds encouraging Mark - thanks - I'm going to send a query to Siebert!  I wasn't sure if I'd go for Ha: I've definitely got the bug though now. I read someone here describe it as 'Jupiter on steroids' - a great phrase!  So dynamic, changing by the hour - you just never know what you might catch!

I'd dearly love the LS60DS - I hope it brings you lots of joy and wow moments - congrats again !

Edited October 16, 2017 by niallk

[Highburymark]

41 minutes ago, alanjgreen said:

I think that binoviewing a double stack ls50 will give a very dim image. Probably a step too far. 

My experience with binoviewing the double stack ls60 (with 60mm DS) is that it is very good. I never use single eye anymore for solar.

i also recommend people with ls60 scopes and  ds60 double stacks look into the m90 rotators that allow you to turn the DS unit while looking through the eyepiece- more detail can suddenly appear as you rotate the front DS unit based on the conditions.

its a case of matching both etalons to the conditions to tease out the extra filament or too.

https://www.teleskop-express.de/shop/product_info.php/info/p4295_TS-Optics-360--Rotation-with-M90-thread.html

I was interested to see your rotator Alan. So far I've just unscrewed the DS filter by up to one turn to adjust the view, but a proper clocking mechanism would be very nice - and safer. I too do 95% of my observing with the DS filter attached. Thanks for the idea of getting an old model Steeltrack Newtonian focuser btw - it's perfect for the LS60. 

 

[Highburymark]

Emailing Lunt for new o-rings has thus far been unproductive. So have ordered some of my own from a UK supplier. I've gone for a pair that should match the Lunt o-ring dimensions, and another pair with a slightly wider cross section. Will be interesting to see if the larger ones make any difference (or if they'll just make it impossible to reattach the pressure tuner). Will report back. 

[garryblueboy]

Hi Mark would be interested in how you get on with the new o rings 

[SkyGibbon]

My tilt tuned 60 puts out outstanding views, single or doubled. I almost sent my scope to lunt to have a PT retrofit, but after all the little complaints about the PT models, I am glad I didn't.

[Highburymark]

3 hours ago, SkyGibbon said:

My tilt tuned 60 puts out outstanding views, single or doubled. I almost sent my scope to lunt to have a PT retrofit, but after all the little complaints about the PT models, I am glad I didn't.

How would you describe what you can see single stacked? Are proms, filaments and active regions all clear? How do they compare to double stacked views? It would be interesting to know. While certain differences are to be expected from scope to scope, it may be that buying tilt tuned is a more sensible option if you don't intend to add a second etalon?

Based on my experience of two Lunt pressure tuned scopes, both have been disappointing single stacked, both have required the tuner to be tightened to the very end of the brass cylinder - and both are capable of great views double stacked. Trouble is not everyone can afford that. And if single stack views are poor, does that mean the double stack views I'm getting could be better? I'd like to find out.

[John]

I've been doing a lot of reading on HA solar scopes recently and one thing that has really struck me is the variation in performance reported between individual units, of all brands and designs. I wonder, if you lined up half a dozen examples of the same scope model and viewed through each one under the same conditions, same magnification etc, etc, whether any of them would be exactly the same ?.

Edit: It also occurs that maybe, if you repeated the excercise on another occasion the results would differ again ?

 

 

Edited October 19, 2017 by John

[Merlin66]

The typical bandwidth of a single stack etalon is 0.7 to 1.0A - this is sufficient to show all the major solar features, the wider bandwidth is sometimes better at showing the proms due to their Doppler shift.

A double stack gets down to around 0.5A and this enhances the surface details and may require some "extra" tuning to maximise the views of the proms.

You can double stack external tilt etalons - I used a double stack SM60 pair for many years on the ED80.

(Adding a double stack filter to a poorly performing single stack etalon will slightly improve things but consider the cost v's benefit)

 

[Highburymark]

1 hour ago, John said:

I've been doing a lot of reading on HA solar scopes recently and one thing that has really struck me is the variation in performance reported between individual units, of all brands and designs. I wonder, if you lined up half a dozen examples of the same scope model and viewed through each one under the same conditions, same magnification etc, etc, whether any of them would be exactly the same ?.

Edit: It also occurs that maybe, if you repeated the excercise on another occasion the results would differ again ?

 

 

What you say appears to be true John. No two of the same solar ha model are the same. In fact they seem to be remarkably different - as is obvious from a couple of the posts above and the years of experience I had with the LS50. That's the nature of the technology. And there are so many other variables - seeing, warming up the scope, adjusting focus and the pressure tuner, eyepiece choice, whether the o-rings are holding pressure, magnification, sweet spot manipulation, adjusting the tilt on the double stack, clocking the double stack - any of these can change the result. So you need to be thorough in your testing until you can be sure that the only differences from session to session are purely down to seeing and atmospheric conditions. Everything else is up to the observer.