Solar ha - what can possibly go wrong?

[Highburymark]

A few weeks ago I gave a presentation to colleagues at work on solar astronomy - using a pressure tuned Lunt DS as an example. A couple of people asked how easy it is visually to see the level of detail captured in solar ha images. Obviously I made clear there is normally a vast gulf between the two, as imaging involves sophisticated processing of raw data - but it set me thinking about just how many variables there are if you want to achieve the very best views from the scope. I surprised myself with the final tally - which I will list here just in case they might be useful to anyone else.

1. You need the scope on band. Even tiny shifts in pressure affect what you can see, whether you want to dial in proms or filaments and other surface detail. Importance factor 10/10

2. You need good, steady seeing. Morning and late afternoon best in U.K. 10/10

3. You need to tune the double stack filter for maximum contrast and detail. 10/10

4. You need a solar-friendly eyepiece, not necessarily an expensive one. Plossls and orthos fine. 10/10

5. You need to keep magnification down, unless you have perfect seeing, and a decent sized scope. 9/10

6. You need to set up away from concrete, ideally on grass. 9/10

7. In cold weather you need to heat the blocking filter. 7/10

8. You need to grease the piston to make sure it’s holding pressure. 10/10

9. You need a mount that either tracks the sun, or has slo-mo controls. That thing shifts. 8/10

10. You need an eye patch, a cap, and something to cover your head to block our light and really see detail well. You’ll look ridiculous, but if views are great, you won’t give a damn. 10/10

11. You need to try binoviewing, which most people say increases detail, but certainly makes observing easier, as long as you can reach focus and keep power down. And if you’re binoviewing, don’t forget to remove the eye patch you’ve just donned after reading point 10. 9/10

12. You need to ‘clock’ the double stack filter, and also move the sun’s disk around the fov, to find the etalon’s sweet spot. 8/10

13. You need to get comfortable. The longer you look, the more you see, so settle in. 10/10

14. You’ll need a clear sky. Even thin, high cloud can spoil your view, turning the black background sky red. 10/10

15. You’ll need the sun to be active. It’s currently just beginning to wake up from several years of slumber as Cycle 24 wound down. By 2021/2022, things should be hotting up once again thanks to Cycle 25. 10/10

16. You’ll need  a large glass of Stella Artois/Long Island Iced Tea/Cabernet Sauvignon at your side. 10/10

Reading these back makes me thankful I don’t image. 

 

[PeterW]

I like calcium, so I have to inage! I find hydrogen alpha better with images, but white light better visually. Just tried out my LS60 and the view is fuzzy... blocking filter has gone rusty... hope it’s an easy fix.

To your numbers...

3) if you got a double stack you’ll get great views, we envy you!

5) agree, brightness helps see contrast.

😎 I’ve got the red sludge it came with, what replacement can you recommend?

10) absolutely! Preserves my white on the outside and black on the inside to keep things cool.

15... !! Sunday just a small patch in Calcium, just surface detail in white light... plenty of time to fix the blocking filter before it gets interesting again.

Peter

 

[Highburymark]

Afternoon Peter,, hope you’re keeping well.

If it’s just a case of replacing the blocking filter glass, you need to contact the European importer, Bresser/Lunt in Germany  - they’ll send you a free replacement - it’s an easy fit from what I hear. 

[PeterW]

Waiting for the reply, was passed on by Lunt US. Hammer and screwdrivers at the ready! Had a nice session out galaxy hunting on Sunday, waiting for the moon to move away a bit more.

Peter

[richard ashbee]

Everyone needs a list, a good one at that

[tico]

Hello,

I have been able to observe a lot with a PST 40, and a little lately with a Lunt 50 B600, visually always, not photographically ...
In my opinion, the photographic images of the sun made with both telescopes have nothing to do with what I have been able to see visually ..., always in favor of photographic images ...
Cheers
ethical

 

[jonathan]

Is double stacking essential for solar imaging?  What would be more important - a larger solar scope or double stacking?

[Highburymark]

On 23/04/2020 at 21:52, tico said:

Hello,

I have been able to observe a lot with a PST 40, and a little lately with a Lunt 50 B600, visually always, not photographically ...
In my opinion, the photographic images of the sun made with both telescopes have nothing to do with what I have been able to see visually ..., always in favor of photographic images ...
Cheers
ethical

 

Imaging the sun involves a great deal of processing. Imagers take thousands of frames, choose the best, stack them, sharpen them, add contrast, and colour them. It takes quite a bit of skill, but doesn’t represent the actual view through most small solar scopes. Learning how to get the most visually is a different skill - plus of course there’s a great amount of variation from one scope to the next. Only a small percentage of etalons/scopes/filters - in my experience - really deliver the very best views - which deliver immediately easy to see, clear and contrastful surface detail. Most solar scopes require a bit of investment from the observer, and decent solar activity, to make filaments and active regions stand out. Proms are easier to see in most scopes. But it’s impossible to compare the views through a small scope with photos of the sun,

[Merlin66]

Not esssential.

A single stack still shows surface detail and is good for proms.

As mentioned the DS greatly improves the surface contrast.

Aperture for resolution, DS for surface detail.....

[Macavity]

I think the thing that most "exercised" me was finding a camera that
did NOT produce (infamous) "Newton's Rings"! lol. Eventually I did...
re. a (Sony ICX-445 based) FLIR "Chameleon"Cam. Were times more
"normal" I'd happily sell off a (now spare) IS 41AU02 to an aspirant?
Older (slower!) technology, but it still (also) worked well enough... 😎

Edited April 25, 2020 by Macavity

[Highburymark]

7 hours ago, jonathan said:

Is double stacking essential for solar imaging?  What would be more important - a larger solar scope or double stacking?

Larger scope for better resolution, double stack for greater contrast. Larger scope AND double stack for bankruptcy.

[jonathan]

2 hours ago, Highburymark said:

Larger scope for better resolution, double stack for greater contrast. Larger scope AND double stack for bankruptcy.

Yeah, when I bought my LS60 single-stacked Lunt it was I think the most expensive scope I've ever bought, have nowhere near enough disposable income now even to afford half that.

[Highburymark]

2 hours ago, jonathan said:

Yeah, when I bought my LS60 single-stacked Lunt it was I think the most expensive scope I've ever bought, have nowhere near enough disposable income now even to afford half that.

The only consolation Jonathan is that they are a fraction of the price they were a decade or two ago.  Despite the pain of financing a solar scope, we have to count ourselves lucky to be able to see the sun in h alpha at all

[PeterW]

DMK41, still works fine, low frame rate, but still make good results.The stack processing with autostakkert is very simple to learn. The recent BAA webinar (on YouTube) showed how to process Venus data similarly.

Peter

[jonathan]

On 25/04/2020 at 22:39, Highburymark said:

The only consolation Jonathan is that they are a fraction of the price they were a decade or two ago.  Despite the pain of financing a solar scope, we have to count ourselves lucky to be able to see the sun in h alpha at all

But I bought mine almost a decade ago!

[Highburymark]

5 hours ago, jonathan said:

But I bought mine almost a decade ago!

Maybe the better comparison would be between today and two decades ago, before there were two mainstream companies competing with a range of solar ha telescopes. 

[steveex2003]

On 25/04/2020 at 20:12, jonathan said:

Yeah, when I bought my LS60 single-stacked Lunt it was I think the most expensive scope I've ever bought, have nowhere near enough disposable income now even to afford half that.

Hand on heart, do you have any reservations on that purchase? At all?
I've been sitting on the fence for 18 months now, with always a backroom want for a solar scope. There is a current offer on a Lunt50/600 which is within the realms of affordability to me (although i really should probably sell a scope or two that rarely get used 🙂 ) 
I have been fortunate that thus far no scope, EP, mount etc has been a disappointment. Ultimately, i just prefer A over B etc. Along with an Equinox 120 this would equate, almost pound for pound  to be my most expensive single scope purchase. I haven't regretted a single penny of the Equinox. I just would hate to invest that money for a sense of MEH.
I have no access to such a scope to try in the flesh. I have invested 18 months into reading about solar observation, and am very attracted to the idea of owning such a thing.

 

Thanks

Steven

Edited April 29, 2020 by steveex2003

[BGazing]

10 hours ago, steveex2003 said:

Hand on heart, do you have any reservations on that purchase? At all?
I've been sitting on the fence for 18 months now, with always a backroom want for a solar scope. There is a current offer on a Lunt50/600 which is within the realms of affordability to me (although i really should probably sell a scope or two that rarely get used 🙂 ) 
I have been fortunate that thus far no scope, EP, mount etc has been a disappointment. Ultimately, i just prefer A over B etc. Along with an Equinox 120 this would equate, almost pound for pound  to be my most expensive single scope purchase. I haven't regretted a single penny of the Equinox. I just would hate to invest that money for a sense of MEH.
I have no access to such a scope to try in the flesh. I have invested 18 months into reading about solar observation, and am very attracted to the idea of owning such a thing.

 

Thanks

Steven

If you already have a refractor, you may consider getting a Quark. @FLO is stocking them now. The views are certainly not MEH and the detail you might get on your Equinox would surpass your expectations. At 120mm you might still use only internal ERF.

[steveex2003]

I had considered such a thing, as well as a Daystar, and have watched several sail by in the Classifieds here and elsewhere. Ultimately I have been put off, rightly or wrongly, by the on band warm up/adjustment time  it also appears that the availability of secondhand Quarks is higher. Again, rightly or wrongly, it does seem that those that buy Lunts tend to keep hold of them. YMMV.

 

Steven

[Solar B]

Great checklist Mark ... I had forgotten about clocking ! 

Just remember not to clock too far esp with any new DS arrangements 😎

Brian 

[jonathan]

23 hours ago, steveex2003 said:

Hand on heart, do you have any reservations on that purchase? At all?

Not at all.  I spent a long time researching the various solar telescope options, from Baader white light filters to double stacked dedicated Ca scopes, I landed on the Lunt LS60 as it seemed to offer the best views and feartures for the money (I would like to have gone for a larger aperture but they were just too far out of my reasonable budget).

The only caveat with any solar observing equipment is that there will be weeks, months, or even years when it might see little or no use, such as during periods of poor weather, solar minimum (such as now, but it is coming to an end soon), or 'solar burn out' (such as during a solar maximum - seen one too many filaments!)

My Lunt has suffered from corrosion on one of the glass elements, a known fault with them which I hear has now been corrected by the use of a coated element, I have just now fitted the replacement (coated) glass element to my Lunt, a very easy procedure.  Looking forward to some warm clear days soon so that I can try it out!

Make no mistake, when a scope such as the Lunt works (i.e. blue glass filter isn't corroded) and there is activity on the sun to observe, it's a fantastic sight and a joy to use.  The Pressure Tuner system I have makes tuning into the various features very easy, I was reading the manual again just recently and it spoke of being able to tune into the entire length of a filament in a '3D' sense, so you could start at one end of the filament and 'tune' along the length of it, this is something I really want to try but it might be next year or later before we see long filaments start to appear again.  In the mean-time there's still the occasional sun spot to observe, prominences, and the granularity of the solar 'surface' to admire.

If you have the cash to splash and patience to wait for the solar activity to heat up over the next few years then I say grab a scope now, as the price and availability might just change as interest increases towards the solar maximum.

 

Oh and I looked at the Equinox 120 as well, in the end I went for the Altair Astro 102 APO for reasons of weight and price, and stuff that was included (dual speed 2" focuser is rather nice to have).

Edited April 30, 2020 by jonathan

[steveex2003]

Thank you for your considered reply.

Steven