34 replies to this topic

[blakestree]

Howdy,

 

I believe I'm suffering a bit of analysis paralysis. I've run the numbers, backwards and forwards, and I thought I had decided on a Quark Chromosphere hooked up to an AT80ED, for a dedicated solar scope. It seems that many of you, however, would rather recommend double-stacking a Lunt 50, for around the same money. For a purely visual observer, is it really worth giving up the extra 30mm resolution/mag. potential for the added contrast of a double stack? I just wanna see the most I can for under 2 grand...

 

I appreciate your insight.

[wrnchhead]

All I can comment on is my PST. The double stacking a whole different experience. Was just out observing earlier and with the new activity that is going on, the double stack is stunning. 6 months ago when proms was all I had ever seen, the double stack was good, great views of a boring surface, but not with the new action, it's great. 

[LunarObserver]

I had a Lunt 50 PT double stacked, very nice images.  I sold it and have a Quark chromosphere with 80 mm scope.  The Daystar gives more pleasing views in my opinion, the larger aperture helps.  It is fun and easy to see spicules.  I know that you will get many different responses, but this is my two cents worth!

Clear skies,

David

[blakestree]

Thank you both for your responses. And, David, I really appreciate your real-world experience with these two particular setups.

Edited by blakestree, 02 December 2020 - 11:43 AM.

[MalVeauX]

Howdy,

 

I believe I'm suffering a bit of analysis paralysis. I've run the numbers, backwards and forwards, and I thought I had decided on a Quark Chromosphere hooked up to an AT80ED, for a dedicated solar scope. It seems that many of you, however, would rather recommend double-stacking a Lunt 50, for around the same money. For a purely visual observer, is it really worth giving up the extra 30mm resolution/mag. potential for the added contrast of a double stack? I just wanna see the most I can for under 2 grand...

 

I appreciate your insight.

It's a personal thing.

 

One pathway is to get the biggest aperture you can, to resolve things the best, if seeing conditions allow. This is indeed a great way to see prominences on the limb. However, it can be difficult to really view subject matter on the face of the disc due to being lower contrast as a single stack, but with experience and HA-eye-adaptation (similar to dark adaption) you can see every structure in HA.

 

The other pathway is to get a smaller aperture and double-stack it to get the highest contrast you can on the surface of the disc, by eliminating the parasitic continuum that is leaking through.

 

For the same price, getting a dedicated instrument with a double stack will give full disc views that are bright and with really high contrast. The difference is rather stark. Filaments are very dark and high contrast, plages are very bright and high contrast, the disc surface is dimmed appropriately and the proms pop out on the limb without being overwhelmed with brightness from the disc. You give up resolution. However, you will still see and resolve the structures of the chromosphere with a 50mm no problem.

 

The only way to know is to experience it. It would help to be able to visit a club or member who has one or the other so you can take a look.

 

For me, HA is all about the massive active regions and the structures found near them (chromosphere network, plages, filaments, fibrils, spicules and prominences (which are filaments) near the limb). So for me, HA is better as a wider field of view to see the entire enormous structure. HA for me is not about the sunspot, which is a photosphere feature. So for HA viewing, I much prefer a double stack with smaller aperture, compared to a single stack much larger aperture. The only exception would be really complex prominences where aperture single stack is great (because there's no photosphere behind a prominence, so its not overwhelmed with brightness from the continuum leaking through). But, the surface is where all that HA activity and structures are, and so again, for me, a double-stack wins there. Just my personal preference.

 

Since the option of a Quark is involved, which cannot be double-stacked easily, this means you are on the pathway of a single stack with larger aperture. It's different if we were talking about a 80mm or 90mm single stack etalon that could potentially be double stacked later, as that would be superior in general. Unfortunately double the cost too.

 

My range of instruments for solar viewing goes from 200mm to 40mm, single and double stacked in various ways. My biggest aperture doesn't get used visually much because it's a single stack and simply lacks the contrast that a double stack has, and because of its fine image scale and high magnification its very seeing limited and also the field of view is narrow so many structures do not fit in the field of view, and again, HA structures are often enormous. So if I'm doing single stack larger aperture viewing, I usually will use a 102mm~150mm aperture range with binoviewers. However, ultimately I much prefer viewing the entire disc and all the structures all at the same time in very high contrast with a smaller aperture double stack system and binoviewers, and for that, I use 60mm aperture etalons.

 

Ideally I'd want an 80mm~90mm double-stack for all of it. But ultimately that costs too much for me right now. But that's the size I would target for "life."

 

8" with a Quark and Binos:

 

 

60mm Double Stack with Binos:

 

 

Very best,

[Gregory Gross]

Having had a DS'ed 50mm Lunt before bumping up to a DS'ed 60mm Lunt--and as someone who definitely prefers full-disk visual observing with only occasional attempts to create crude images using a mirrorless camera body--I'd add that Marty's comments about sacrificing resolution for contrast ring true for me, too.

 

I distinctly recall that, when I was discussing my own choice with the good folks at Lunt, they told me that more aperture really helps with resolution especially when one is interested in detailed, higher-magnification views of specific features that might appear on the Sun any given day. If you want a good look at an impressive prominence or active area, aperture will really help you.

 

But I prefer to sit there and let my eye wander around the full disk of the Sun at lower magnification. Having been spoiled by DS'ed views, I would never think of going back to a single-stacked setup even if it meant I could get more aperture. Having a smaller, easily managed, lightweight setup that I can pop onto a small mount is what suits my personal tastes best. My DS'ed 60mm Lunt hits the sweet spot for me in terms of having enough aperture for satisfying, well-resolved, lower-magnification views with good contrast uniformity across the whole disk of the Sun. It weighs in at around 9 lbs, and its cost was just about as much as I could stomach for a DS'ed solar scope. It's just a delight to use.

 

I was getting similar performance out of my DS'ed 50mm Lunt, but I found that the well-tuned sweet spot was just a bit smaller than the width of the Sun's disk itself, thus my upgrade to the 60. But I confess there's a little bit of me that regrets trading in my DS'ed 50 for my current 60. I had a sentimental attachment to that little scope, and it punched way above its weight in terms of the performance it delivered. It's a contender, too (pardon me for stretching the boxing metaphor too much).

 

Whether the choice is a DS'ed 50 or 60, I really like the combo of pressure-tuned primary etalon with tilt-tuned front-mounted external DS module. I never have any problems getting that most satisfying tuning set.

 

While I don't have hands-on experience using a Quark, the fact that one needs to power it with a battery and the fact that one has to wait a few minutes for the etalon to heat or cool in between tuning knob selections when one is getting optimal tuning dialed in were two factors that deterred me from going the Quark direction. And Lunt is just an awesome company to work with, though Daystar, I hear, has solid customer service, too.

Edited by Gregory Gross, 01 December 2020 - 04:35 PM.

[LunarObserver]

All of the above comments are great and valid.  I will certainly agree Lunt and Daystar give great customer service.  Attached below is my solar drawing for the day, white light and Daystar Quark chromosphere.  Really nice views.

David

Attached Thumbnails

• 

[Spikey131]

The Quark will show you plenty in the refractors you already have.  Nice surface detail and proms.

 

The best resolution for your money.

[blakestree]

I enjoy a full disk view, as an "establishing shot" to put everything into context. And, I would even be able to pull that off with my TV-60 and a Quark. But, I'm sorta surprised full disk provides enough detail for you, Marty and Gregory. What magnification do you guys use most? With an 80mm scope, I believe I'd be able to comfortably push 100-120X on all but the worst seeing days. Do you believe surface detail would be too washed out, with a Quark, at those powers? More a matter of restricted FOV? Do you feel ~100x is just too much for Ha visual?

[MalVeauX]

I enjoy a full disk view, as an "establishing shot" to put everything into context. And, I would even be able to pull that off with my TV-60 and a Quark. But, I'm sorta surprised full disk provides enough detail for you, Marty and Gregory. What magnification do you guys use most? With an 80mm scope, I believe I'd be able to comfortably push 100-120X on all but the worst seeing days. Do you believe surface detail would be too washed out, with a Quark, at those powers? More a matter of restricted FOV? Do you feel ~100x is just too much for Ha visual?

Again it's purely personal. My seeing is generally rather good, and with a small aperture like 60mm and binos, I can make out the fibrils and filaments and the chromosphere network around active regions quite well. Sure, if I increase magnification I can see them better, but it remains that I can see all the main structures in HA as a full disc with everything within the sweet spot so I just look anywhere I want, no tracking around, no panning. This is just my preferred way to view visually. It's comfortable with binos and the contrast from the double stack makes it so easy to see structural differences and details as the contrast is high. I'm happy looking at a disc at a mere 25x magnification even with binos.

 

Viewing at 50x and 100x magnifications is no problem with my larger scopes and the limb is sharp and I can see the spicules on the limb no problem, they are sharp and great, with a single stack and a bigger aperture scope (80mm, 120mm, 150mm, 200mm). The contrast is lower, significantly lower, and so resolution helps a lot to make up for the loss in contrast, so that details are resolved. But you need to have your eyes HA-adapted (like dark adapting) to really be able to definitively make out some structures without just seeing a wash of low contrast with some lines. I prefer to see pencil line drawing kind of contrast, and that's just not how it is with a single stack. It's really hard to put in words the difference between a single stack and a well-tuned double stack. It's a completely different experience and it's so hard to go back to single stack even at the cost of resolution with how contrasty the double stack solution is. But again, I'm happier looking at a low resolution, low magnification full disc with every feature in view with high contrast in a double stack, over my much, much larger single stacks. There's no logic to it other than personal preference.

 

You'd have to truly just try both views to know what matters to you more. It's very personal and unique to what you want.

 

And for visual use, since you cannot process the image, getting the best etalons and best equipment for your budget is a big deal because you'll just get what you get from the system visually. For this alone, I would push towards Lunt. I've used etalons from everyone at this point except a handful and at the end of the day if I had to pick any of them to live with, it would be the Lunt and their company and support. Not even close honestly at this point. And prices are frankly outrageous for what's coming out these days from most everyone with non-support or low quality everything to begin with.

 

 

Very best,

Edited by MalVeauX, 01 December 2020 - 10:52 PM.

[Gregory Gross]

I use a Lunt zoom eyepiece with my 60mm scope. 95% of the time I use it at its lowest magnification (21.5mm). Rarely do it set its focal length lower than 17.5mm. But my seeing where I am here in the Pacific Northwest is not that great, and I find that especially my daytime seeing coupled with my smaller DS'ed aperture doesn't really support those higher-magnification views. Given these factors, I'm quite happy with a smaller aperture.

 

This is purely subjective, I know, but I also like the idea of a dedicated solar scope. Knowing that a thoughtful and expert designer has conceived of a system whose parts work together end to end is something I like looking at just as much as I do using.

 

As Marty suggests, it's all personal preference. Some on this forum love pushing magnification even on their 60mm instruments with some succeeding even with smaller apertures. One thing I've learned is that the aperture-is-king rule is kind of suspended where solar astronomy is concerned. A 90mm scope is a small scope for nighttime use. But it's a big one (and an expensive one) for solar.

 

But even at my low mags, I feel deeply satisfied with the amount of solar detail that my 60mm DS'ed system provides me. It's the contrast more than anything else that draws me in. Seeing the swirling fibrils around active areas, subtle and delicate qualities in filaments, dark sunspots set in bright and angry plage regions, and other chromospheric features are all so very much more visible and satisfying to observe in a DS'ed instrument. Prominences, while a bit dimmer, still stand out to the extent that I can still make out faint ones even with the neutral density filter I typically use. Again, for me personally, that contrast is far more important than my ability to resolve at higher magnifications given my liking for full-disk views the most.

 

At risk of tooting my own horn too much, I recently posted some reflections of mine about my journey in H-alpha solar astronomy on my website. They may be useful to you.

 

For those high-mag views, I rely on the incredible images that my friends here on the solar forum post. I feel like I'm cheating in that respect: I *can* have my cake and eat it, too!

[Gregory Gross]

One other thought: when I got my start in H-alpha, I wanted to keep my total costs below $2K as you do now. The 50mm Lunt was the perfect way to get my feet wet and get some meaningful experience. I eased my way into things and used my scope in single stacked mode first. I then made upgrades here and there until I got to my $2K limit (DS module, FT focuser, case, Lunt zoom EP).

 

I think that's one of the wonderful things about the 50mm Lunt: it's a quality piece of gear that is super flexible in terms of upgrades but is still reasonably priced for those who are unsure about spending a ton of money on gear made to look at one object.

 

Especially as we get some activity on the Sun, I would expect there to be a solid market for used 50mm Lunts. So if you dive in like I did with a 50mm, you have reasonable assurance that you'll be able to sell it if you find you want something else.

[Zyx]

Great article on your site, Gregory. It answered a lot of my questions on whether to double-stack my Lunt 60mm modular — and convinced me I’m going to have to do it. First I’ve got to pay off the Lunt along with the binoviewer and extra eyepieces I just ordered.

[bigdob24]

I enjoy a full disk view, as an "establishing shot" to put everything into context. And, I would even be able to pull that off with my TV-60 and a Quark. But, I'm sorta surprised full disk provides enough detail for you, Marty and Gregory. What magnification do you guys use most? With an 80mm scope, I believe I'd be able to comfortably push 100-120X on all but the worst seeing days. Do you believe surface detail would be too washed out, with a Quark, at those powers? More a matter of restricted FOV? Do you feel ~100x is just too much for Ha visual?

A good full disk with a DS is hard to beat, but for me I generally increase the mag as much as seeing supports.

With the Denk ll that’s easy with the power switch. 
I have 24, 15 and 10mm eyepieces that take me from 36 to 164 X and most days a bit over 100X works best .

‘I’m looking for a second 6 mm Delos for a high power set that will get me over 200X on those rare days , and there have been days that’s doable. 
When I had my quark on a 132mm scope, could not get a full disk but the high power detail was over the top , that’s why I’m trying to get over 200X with the Lunt 100 on those special days . If it will handle that mag I’m guess that would about max it out , more after I get the eyepiece.

[SloMoe]

Morning, can I ask what eyepiece you all are using on your Quark for full disc views, like what's the glass path from scope to your eye?

[Highburymark]

Great answers in this thread. My experience is as follows - views rated out of five:

Lunt 50: single stack ***, double stack ****
Lunt 60: single stack **, double stack ****
Quark: surface detail **, proms *****
Solarscope SF70: single stack ***, double stack *****

My lovely Lunt 50DS easily beat the Quark (chromosphere) on surface detail, but the Quark in a big refractor shows breathtaking proms - even better than my Solarscope 70mmDS. If I had to keep one of the LS50DS or Quark I’d go for the Lunt without hesitation. But I’ve seen Lunts that disappoint and Quarks that knock your socks off.
Bit like snowflakes and fingerprints, each solar etalon is unique.

[blakestree]

Morning, can I ask what eyepiece you all are using on your Quark for full disc views, like what's the glass path from scope to your eye?

With a Quark you wanna use a long focal length eyepiece, right? Given the Quark's 22mm clear aperture, I believe a 25mm Plossl is about as long as you can go without vignetting. That means, if you stick to Daystar's recommended f7, you'll need an 80mm or smaller objective to achieve a full disk view. Really, you'd probably lean more toward smaller, because 80mm is right on the threshold.

Edited by blakestree, 02 December 2020 - 01:22 PM.

[MalVeauX]

Morning, can I ask what eyepiece you all are using on your Quark for full disc views, like what's the glass path from scope to your eye?

Heya,

 

On a ~400mm focal length, and a 25mm eyepiece, you can get a full disc view with a standard Quark. Note, you can do the same thing with binoviewers too, as you do not need a GPC at all as the Quark already handles that, so you can use your pairs of eyepieces at native focal lengths (so a pair of 25mm plossls for example would do great here).

 

For that, I take an ST80 and it's stock aperture mask brings it to 40mm F10. This is ideal with the Quark because the F10 becomes F43 so that etalon is happy and it should be operating closer to 0.65A~0.7A or so by then and contrast should be pretty good.

 

Significantly longer focal length and you will not get full disc FOV anymore. Quarks really are mostly for higher magnification viewing. But they're designed to be super happy with binos, so definitely use binos either way!

 

 

 

Very best,

Edited by MalVeauX, 02 December 2020 - 01:19 PM.

[blakestree]

Guys, thanks so much for your thoughtful responses! (And, Marty, the wonderful images, too.) They haven't done much to help my indecision, though. Hahaha. Now, I'm asking myself, do I blow my load on a LS60MT and hope one day I can afford to double stack it... 

[rigel123]

Guys, thanks so much for your thoughtful responses! (And, Marty, the wonderful images, too.) They haven't done much to help my indecision, though. Hahaha. Now, I'm asking myself, do I blow my load on a LS60MT and hope one day I can afford to double stack it... 

That would be my choice since I have been happy with my Lunt LS60T that I have had for 8 years and did not double stack it until early 2019!  Especially since things are starting to ramp up on the sun.  I never had any difficulty with mine seeing nice details in SS mode and I have a tilt tune model, but then again I got mine in the middle of solar maximum and there was a LOT to see then!  The DS does enhance the contrast on the surface but I remember my jaw dropping when I took my first look through my SS Lunt too!

[Gregory Gross]

Another thing to consider is that, with a larger and more expensive scope, the jump in cost is due mostly to the larger and better etalon that is in that scope relative to the smaller one. The etalon is far and away the most expensive and most difficult thing to build in a dedicated H-alpha solar scope. I am still in a mild state of shock that manufacturers can even produce etalons given their stringent requirements.

 

So a 60mm Lunt will have a better etalon than the 50mm will.

 

Before Lunt moved to their current modular design, they used a simple singlet objective lens for the 60mm. The 50mm still uses a singlet. With a normal refractor, this would result in disastrously bad chromatic aberration. But in an H-alpha scope, this chromatic aberration doesn't matter since you are only going for an impossibly narrow slice of the spectrum. The optics at the front of the scope can thus be much simpler. So most of the money you're spending to get a dedicated H-alpha scope is going towards the etalon and, to a lesser extent, the optics in the blocking filter assembly.

[Gregory Gross]

Guys, thanks so much for your thoughtful responses! (And, Marty, the wonderful images, too.) They haven't done much to help my indecision, though. Hahaha. Now, I'm asking myself, do I blow my load on a LS60MT and hope one day I can afford to double stack it... 

Not sure if this tips the scales either way, but a friend of mine used a Quark for years before getting a used 50mm Lunt. I remember him commenting that the Quark was definitely not a grab-and-go piece of gear since it required plugging into a power source and time to warm up. Each click of the tuning control also required time for the etalon to change temperature. With a dedicated solar scope (Lunt, Coronado), you are locked into whatever aperture you have, but you can be observing in however long it takes for you to set up your mount and fine-tune the instrument. And you don't have the need for a power source.

[SloMoe]

I guess it wasn't fair to ask a "Which Eyepiece" without including the scope being used, I'm using an Orion Skyview Pro 80mm ED.

Focal length 600mm

[MalVeauX]

Not sure if this tips the scales either way, but a friend of mine used a Quark for years before getting a used 50mm Lunt. I remember him commenting that the Quark was definitely not a grab-and-go piece of gear since it required plugging into a power source and time to warm up. Each click of the tuning control also required time for the etalon to change temperature. With a dedicated solar scope (Lunt, Coronado), you are locked into whatever aperture you have, but you can be observing in however long it takes for you to set up your mount and fine-tune the instrument. And you don't have the need for a power source.

This was also a big deal for me and why I went away from Daystar in general, or any electronic controlled etalon for tuning. One less thing to repair. No waiting time for the temperature changes. And of course, getting away from needing F30 or longer light beams just to get your etalon to be on spec, so needing either tiny apertures or enormously fine image scales with long focal lengths and elaborate reduction schemes after, etc.

 

I love just inserting my etalon(s) and there's no wait time, ready to go.

 

Very best,

[MalVeauX]

I guess it wasn't fair to ask a "Which Eyepiece" without including the scope being used, I'm using an Orion Skyview Pro 80mm ED.

Focal length 600mm

An ED80 with a Quark and a 32mm plossl should be able to just barely squeeze the disc into the FOV. It will be tight though. That's 80x magnification. And realistically, a wider eyepiece than a 32mm won't do much good. You could try a 40mm plossl, but it's likely not going to be much different due to the overall imaging train size.

 

Truly if you want an easy full disc, with a Quark, go for a ~ 400mm focal length. It'll need to be around F7 to get to F30 ideally. But this will allow you to full disc view with a 25mm or 32mm and binos if you want. Those AT72ED scopes with 2" focusers are good targets. The ST80's are good targets for this (with a focuser upgrade though). Any good 400mm focal length with a good 2" focuser basically, because you can mask them to F7 yourself anyways.
 

Here's an ED80 with Quark and 25mm:

 

 

Very best,

Edited by MalVeauX, 02 December 2020 - 03:14 PM.