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Buying a Lunt 50mm --> Should I double-stack?

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#1 Bokchoy Ninja

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Posted 29 May 2020 - 10:32 PM

The age old question...

 

Before spending an extra $800 I'd like to solicit some opinions regarding whether it is worthwhile to purchase a double stacked etalon for the Lunt 50mm pressure tuned scope.

 

I will be doing both visual observing and hopefully imaging.

 

Before anyone suggests it, I have to say upfront that the $1500 price point is the absolute highest I'm willing to put into this particular hobby, so please bare that in mind!

 

And just to be explicit about what I mean when asking whether it is worthwhile, I guess I'd like to know how much improvement I'd be getting. Is it a slight improvement or a drastic one? Is the experience twice as enjoyable when double stacking as when single stacking?

 

Thanks!


Edited by Bokchoy Ninja, 29 May 2020 - 10:37 PM.


#2 Bokchoy Ninja

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Posted 29 May 2020 - 10:39 PM

Edit: also a bit curious to see compared the single-stacked Lunt 50 versus the double stacked Coronado PST, as they're similarly priced. Are they comparable in image quality/contrast?



#3 sunnyday

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Posted 29 May 2020 - 10:43 PM

the pst was not designed for photography (it is possible to do so) but not very practical.



#4 statfreak

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Posted 30 May 2020 - 12:42 AM

The age old question...

 

Before spending an extra $800 I'd like to solicit some opinions regarding whether it is worthwhile to purchase a double stacked etalon for the Lunt 50mm pressure tuned scope.

 

I will be doing both visual observing and hopefully imaging.

 

Before anyone suggests it, I have to say upfront that the $1500 price point is the absolute highest I'm willing to put into this particular hobby, so please bare that in mind!

 

And just to be explicit about what I mean when asking whether it is worthwhile, I guess I'd like to know how much improvement I'd be getting. Is it a slight improvement or a drastic one? Is the experience twice as enjoyable when double stacking as when single stacking?

 

Thanks!

 

Others here may have some creative solutions for you but the fact is that this is an expensive hobby if you want to view or image in H-alpha. If $1500 is your absolute budget all-in then you should let any imaging aspirations go unless you already have other astronomy equipment. For example, if you already have a good, sturdy tracking EQ mount and possibly an 80-150mm refractor, you might want to get into the hobby with a quark, although you'll still need a CCD imager. If you have the mount and imager but no refractor, the Lunt LS50 DS would work for imaging.

 

If you're starting from scratch, a PST double stack is a nice entry level setup for visual use. Once you start up the scale, things get expensive quickly and most who consider the Lunt LS50 quickly move towards the LS60 as there is a significant jump in quality. I honestly don't know if you could get a used LS60 with a front LS50 double stack for $1500 but you really ought to consider the LS60/50 option.

 

<EDIT> Double stacking really does make a difference. Most people never go back to SS after adding the DS.


Edited by statfreak, 30 May 2020 - 12:54 AM.


#5 Bokchoy Ninja

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Posted 30 May 2020 - 01:01 AM

Others here may have some creative solutions for you but the fact is that this is an expensive hobby if you want to view or image in H-alpha. If $1500 is your absolute budget all-in then you should let any imaging aspirations go unless you already have other astronomy equipment. For example, if you already have a good, sturdy tracking EQ mount and possibly an 80-150mm refractor, you might want to get into the hobby with a quark, although you'll still need a CCD imager. If you have the mount and imager but no refractor, the Lunt LS50 DS would work for imaging.

 

If you're starting from scratch, a PST double stack is a nice entry level setup for visual use. Once you start up the scale, things get expensive quickly and most who consider the Lunt LS50 quickly move towards the LS60 as there is a significant jump in quality. I honestly don't know if you could get a used LS60 with a front LS50 double stack for $1500 but you really ought to consider the LS60/50 option.

 

<EDIT> Double stacking really does make a difference. Most people never go back to SS after adding the DS.

Thanks for the reply. My current imaging arsenal includes a SkyWatcher EQ6-R mount, an Explore Scientific 80ED triplet refractor, a modified DSLR, and some small monochrome cmos sensors I've used for guidescopes.

 

I have considered the quark chromosphere, but the fact that it requires electric power and takes a long time to "warm up" between adjustments seems to be a big potential annoyance. Maybe not?

 

I don't think I'd get full disc viewing with my 80ED given its focal length and the barlow built into the daystar, which is unfortunate. I also like the portability of the Lunt 50 as I can easily bring it on trips to show it off to family, etc., while mounting it on an inexpensive camera tripod.

 

I had considered getting a Lunt 60 single stack, but Lunt no longer sells these as they've moved their product line to "modular" scopes for night and daytime use. A used one would be a good option. But I'm a bit surprised there would be a huge jump in viewing or imaging quality between the 50 and 60.
 


Edited by Bokchoy Ninja, 30 May 2020 - 01:01 AM.


#6 Bokchoy Ninja

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Posted 30 May 2020 - 01:14 AM

Right now I have my eyes on a Lunt 50mm + double stack, since it's within my budget, seems pretty portable, and doesn't break the bank.

 

I guess what I want to know is, assuming I'm not going to dive into the rabbit hole but instead just want to have fun viewing the sun and getting some cool occasional images, will I be satisfied with this product, or kick myself and immediately itch for something better?


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#7 statfreak

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Posted 30 May 2020 - 01:15 AM

The Lunts are definitely portable and easily set up for family/public viewing without worrying about heating or power.

 

MalVeauX and our other experts can explain the differences better than I can but the construction of the LS60 is a major step up, so it's not just the 10mm of aperture. You're already have an excellent imaging mount in that EQ6R so, pending the experts' explanations of the quality difference, I'd really consider a used LS60 with the LS50 front stack, even if it tips the $1500 limit. I'm going to assume that the $1500 limit doesn't include the CCD imager, and people here get excellent imaging results with that scope. I believe that you would need two CCD cameras to do both full disk and AR imaging.



#8 Bokchoy Ninja

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Posted 30 May 2020 - 01:17 AM

The Lunts are definitely portable and easily set up for family/public viewing without worrying about heating or power.

MalVeauX and our other experts can explain the differences better than I can but the construction of the LS60 is a major step up, so it's not just the 10mm of aperture. You're already have an excellent imaging mount in that EQ6R so, pending the experts' explanations of the quality difference, I'd really consider a used LS60 with the LS50 front stack, even if it tips the $1500 limit. I'm going to assume that the $1500 limit doesn't include the CCD imager, and people here get excellent imaging results with that scope. I believe that you would need two CCD cameras to do both full disk and AR imaging.


Right on, thanks for the advice. Where should i look for the used 60mm?

#9 statfreak

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Posted 30 May 2020 - 01:26 AM

Right now I have my eyes on a Lunt 50mm + double stack, since it's within my budget, seems pretty portable, and doesn't break the bank.

 

I guess what I want to know is, assuming I'm not going to dive into the rabbit hole but instead just want to have fun viewing the sun and getting some cool occasional images, will I be satisfied with this product, or kick myself and immediately itch for something better?

I know the feeling. It's hard to answer that question. I looked at the LS80 and LS100 and ultimately bought the 80 because they were selling them off at a 25% discount, along with the same discount on the DS and I couldn't say no. Holding out for the LS100 would have cost significantly more because the old units were already sold out. I haven't looked through an LS100 but I can say that I really love my LS80. 

 

So will the LS60 be enough? Only you can answer that. It's a good scope and has an advantage over the LS80 when used with the front DS because there is no glow. The LS50? I honestly think you'll wish you had bought the LS60 from what I've read on this forum. But I have no experience with the LS50 and only looked through an LS60 once.

 

You'll need the larger blocking filter either way if you're going to image. That will add to the price.



#10 statfreak

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Posted 30 May 2020 - 01:28 AM

Right on, thanks for the advice. Where should i look for the used 60mm?

Here on CN in the classifieds and Astromart would be where I'd start. You can post a WTB. 



#11 MalVeauX

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Posted 30 May 2020 - 07:34 AM

Heya,

 

It all comes down to perspective and of course budget always rules. That said, slowing down and really thinking about what you want to get into matters a lot and will help steer your choices. While the Lunt 50mm is a decent instrument, it has compromises that for some are deal breakers. Unfortunately budget tends to steer people right into these instruments for this very reason and they're decent for visual use but they're much more difficult for practical imaging. That said, imaging can certainly be done, it just takes a lot more fuss to get it operational for that in a way that you may actually like with results that you are expecting. Expectation is also a big part of this. What draws you to want a solar scope? What do you like to see the most? Especially during the solar minimum right now with low activity? Knowing what's interesting to you also helps figure out what it is you may wish to steer towards.

 

This is merely my opinion/experience with this, so please take it with a grain of salt.

 

Visually, any of these instruments are wonderful frankly. Looking through a 40mm or 50mm aperture Lunt or PST is actually quite nice visually. You get a full disc FOV and can see the main structures. They're small and fairly light weight and rather easy to use with a little sun finder. Impressive to look through, especially as the maximum returns with more activity; during the minimum cycle (now) activity is low so there's less to see, but there's at least always something to see in Halpha, if even just a prominence here and there and it changes hours and daily rather significantly.

 

The issue is most of these entry instruments were not designed for imaging in mind, so while people find work arounds and get it to function, they do it with significant compromise. The Lunt 50's biggest issue is that it has a helical focuser and the imaging train is hard to use a camera with to be able to come to focus on the sensor, requiring a break down of the pieces of the blocking filter to gain some back-focus into the light cone and having to deal with the helical focuser for precise focusing and any potential sag/tilt which will induce issues too. The focuser is replaceable, but it's never inexpensive to change that to a quality focuser that can handle imaging loads with precision. You can double stack the 50mm later on nicely. The other compromise is that the focal length and small blocking filter means you have to use tiny pixel sensors to ideally sample the wavelength (656nm) but at the limit of the blocking filter's diameter, so its very limited in size (4mm to 6mm depending on which you get). That said, at least the sweet spot is a bit bigger than what the PST has, so its a bit more friendly to imaging full discs. To make the Lunt 50 a great imaging OTA, it would honestly require a few things over time: 1) new focuser, ideally a custom crayford, costly; 2) a larger blocking filter (I would shoot for 12mm; costly); 2) and of course a double stack module. From there, a good camera for it will not be inexpensive, because of the short focal-ratio, to properly sample the wavelength would take tiny pixels and most of these current tiny pixel cameras are not without issue (ie, IMX178).

 

The PST and it's double stack SM40II module is actually fantastic visually, a real double stack view (high contrast) for an entry price. Visually it is actually a nice instrument for this purpose. Imaging is a lot more difficult unfortunately. The focusing mechanism on the PST is an internal pentaprism that is moved by an internal screw with the focusing knob. That's it. A moving big chunk of prism. There's a lot of slop to it, shifting, and if it's not square there will be issues and these are notoriously not put together with precision in mind. The blocking filter is 5mm and cannot be changed stock. So the distance of the light path and the pentaprism focuser and then the eyepiece stalk to the blocking filter is significantly long, so imaging with the PST requires compromise just to get focus with a camera. You either are forced to use a barlow to bring the focus point away from the instrument, but you're still limited to that 5mm blocking filter size, or you have to use a specific camera with small pixels and a low profile adapter to allow it to have more back-focus travel to get in range to focus on the sensor. The transmission on the PST and double stack will be fairly low usually, again, designed to be a visual instrument and the sweet spot is very small, so its not ideal to image with, but can be done. Nothing can be swapped on this instrument, so you're stuck with its focusing mechanism and imaging train and blocking filter size. Its the most limited of all instruments in this category.

 

40mm aperture's resolution to 50mm aperture's resolution is a 25% jump. Going from 50mm to 60mm is a 20% jump. Going from 40mm to 60mm is a 50% jump in resolution.

 

Every incremental increase in aperture matters significantly!

 

Now, the 60mm instrument options are far more friendly to imaging. The Solarmax and Lunt options at 60mm, even the old ones, are much better than the 40mm/50mm options listed above. They have more after market options, blocking filter size options, focuser options, etc. They're frankly a much better base instrument to start with that can be added to over time as you please. For anyone seriously concerned about spending this kind of money and not being underwhelmed with their purchase, I would avoid the Lunt 50 and/or PST if your goal is imaging. Visually they can be satisfying. But for imaging, I highly suggest passing them up and moving towards the 60mm option scopes from Coronado/Solarmax and Lunt. These instrumenst are frankly just a lot better and more friendly to imaging due to being able to control and swap more parts of the OTA and imaging train for the purpose of imaging. So even a used old Lunt tilt tuned version, or an old Solarmax II series version would be better than a PST or Lunt 50 for this purpose. And the aperture really does matter a lot here, that 60mm is significantly more resolution than 40mm and 50mm.

 

Lastly you have the Quark option. It's at the similar price point. It is modular and allows you to pick the OTA which means you choose aperture, you choose focal-ratio, you choose the focuser. This gives a lot more freedom on which camera(s) are ideal for your setup, and of course, which overall scope you want to use. Visually they're good, especially for looking at large structures in higher resolution as this is the least expensive way to get larger apertures (and 70~102mm apertures in solar is actually very big). Yes, they require power and time to warm up to temp to be on band. About 5~7 minutes usually. Imaging wise, the Quark is a gateway choice to high resolution imaging if your seeing conditions support larger apertures. Imaging with an 80mm, 102mm or 120mm for example is a very different output than something only 60mm. So if your interest is single large structures highly magnified and higher resolution, this is an option that outpaces smaller apertures for this price point. Compromises will be that imaging a full disc with a Quark is very difficult, requires compromises to achieve due to the focal length (Quark's have an internal 4.3x telecentric amplifier, so you're always working with long effective focal length, which makes full disc imaging hard). This would require multiple OTAs to control FOV, such as a very tiny short OTA for full disc viewing/imaging and still requires focal reducers and spacers to accomplish that, with an effective 12mm aperture blocking filter, so larger sensors can be used (which is good for flexibility). And another OTA with larger aperture (and a really good focuser) to do high resolution or simply larger magnification views of the partial disc, with significantly longer focal-lengths. The other big compromise is that there's no commercial way to double-stack this without getting another HA filter of some kind and working it into the imaging train while maintaining aperture (the common way to double stack would be to have a dedicated HA telescope and use the Quark with it, effectively double stacking, so like the 60mm or 90mm options out there). There's also of course a few people who have used two Quarks together (one being the Combo version without the 4.3x telecentric internally) with passable results, but I don't suggest this at all really. The Quark really should be looked at as a single stack solution with higher resolution options due to being able to use larger apertures right away. This can be good for imaging. Visually it can be good, but since its single stack it will be lower contrast. There's always compromise in some way.

 

Personally, I vastly prefer visual of the sun with a double stack and smaller aperture, I like seeing the whole disc and all the features at once with high contrast. So for me, I much prefer to use my 60mm double stack visually than my larger scopes. I have larger scopes ranging from 80mm to 200mm in HA that are single stacks and I image high resolution often. But visually they're not as appealing with less contrast. So this is again greatly personal preference, someone else may prefer totally different options. But having a 200mm solar scope and all options below that, visually I frankly prefer to do visual with a smaller double stack. The contrast is the king for me. Imaging, I like full discs, but I also really like moderate aperture for resolution, so I like being in that 120mm aperture range for imaging and my seeing supports larger apertures fairly common here in Florida in the mornings.

 

So again, food for thought and take it with a grain of salt. It all comes down to what you want the most out of what you're looking to get into and what your expectations are.

 

Very best,


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#12 Bokchoy Ninja

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Posted 30 May 2020 - 09:48 AM

Heya,

 

It all comes down to perspective and of course budget always rules. That said, slowing down and really thinking about what you want to get into matters a lot and will help steer your choices. While the Lunt 50mm is a decent instrument, it has compromises that for some are deal breakers. Unfortunately budget tends to steer people right into these instruments for this very reason and they're decent for visual use but they're much more difficult for practical imaging. That said, imaging can certainly be done, it just takes a lot more fuss to get it operational for that in a way that you may actually like with results that you are expecting. Expectation is also a big part of this. What draws you to want a solar scope? What do you like to see the most? Especially during the solar minimum right now with low activity? Knowing what's interesting to you also helps figure out what it is you may wish to steer towards.

 

This is merely my opinion/experience with this, so please take it with a grain of salt.

 

Visually, any of these instruments are wonderful frankly. Looking through a 40mm or 50mm aperture Lunt or PST is actually quite nice visually. You get a full disc FOV and can see the main structures. They're small and fairly light weight and rather easy to use with a little sun finder. Impressive to look through, especially as the maximum returns with more activity; during the minimum cycle (now) activity is low so there's less to see, but there's at least always something to see in Halpha, if even just a prominence here and there and it changes hours and daily rather significantly.

 

The issue is most of these entry instruments were not designed for imaging in mind, so while people find work arounds and get it to function, they do it with significant compromise. The Lunt 50's biggest issue is that it has a helical focuser and the imaging train is hard to use a camera with to be able to come to focus on the sensor, requiring a break down of the pieces of the blocking filter to gain some back-focus into the light cone and having to deal with the helical focuser for precise focusing and any potential sag/tilt which will induce issues too. The focuser is replaceable, but it's never inexpensive to change that to a quality focuser that can handle imaging loads with precision. You can double stack the 50mm later on nicely. The other compromise is that the focal length and small blocking filter means you have to use tiny pixel sensors to ideally sample the wavelength (656nm) but at the limit of the blocking filter's diameter, so its very limited in size (4mm to 6mm depending on which you get). That said, at least the sweet spot is a bit bigger than what the PST has, so its a bit more friendly to imaging full discs. To make the Lunt 50 a great imaging OTA, it would honestly require a few things over time: 1) new focuser, ideally a custom crayford, costly; 2) a larger blocking filter (I would shoot for 12mm; costly); 2) and of course a double stack module. From there, a good camera for it will not be inexpensive, because of the short focal-ratio, to properly sample the wavelength would take tiny pixels and most of these current tiny pixel cameras are not without issue (ie, IMX178).

 

The PST and it's double stack SM40II module is actually fantastic visually, a real double stack view (high contrast) for an entry price. Visually it is actually a nice instrument for this purpose. Imaging is a lot more difficult unfortunately. The focusing mechanism on the PST is an internal pentaprism that is moved by an internal screw with the focusing knob. That's it. A moving big chunk of prism. There's a lot of slop to it, shifting, and if it's not square there will be issues and these are notoriously not put together with precision in mind. The blocking filter is 5mm and cannot be changed stock. So the distance of the light path and the pentaprism focuser and then the eyepiece stalk to the blocking filter is significantly long, so imaging with the PST requires compromise just to get focus with a camera. You either are forced to use a barlow to bring the focus point away from the instrument, but you're still limited to that 5mm blocking filter size, or you have to use a specific camera with small pixels and a low profile adapter to allow it to have more back-focus travel to get in range to focus on the sensor. The transmission on the PST and double stack will be fairly low usually, again, designed to be a visual instrument and the sweet spot is very small, so its not ideal to image with, but can be done. Nothing can be swapped on this instrument, so you're stuck with its focusing mechanism and imaging train and blocking filter size. Its the most limited of all instruments in this category.

 

40mm aperture's resolution to 50mm aperture's resolution is a 25% jump. Going from 50mm to 60mm is a 20% jump. Going from 40mm to 60mm is a 50% jump in resolution.

 

Every incremental increase in aperture matters significantly!

 

Now, the 60mm instrument options are far more friendly to imaging. The Solarmax and Lunt options at 60mm, even the old ones, are much better than the 40mm/50mm options listed above. They have more after market options, blocking filter size options, focuser options, etc. They're frankly a much better base instrument to start with that can be added to over time as you please. For anyone seriously concerned about spending this kind of money and not being underwhelmed with their purchase, I would avoid the Lunt 50 and/or PST if your goal is imaging. Visually they can be satisfying. But for imaging, I highly suggest passing them up and moving towards the 60mm option scopes from Coronado/Solarmax and Lunt. These instrumenst are frankly just a lot better and more friendly to imaging due to being able to control and swap more parts of the OTA and imaging train for the purpose of imaging. So even a used old Lunt tilt tuned version, or an old Solarmax II series version would be better than a PST or Lunt 50 for this purpose. And the aperture really does matter a lot here, that 60mm is significantly more resolution than 40mm and 50mm.

 

Lastly you have the Quark option. It's at the similar price point. It is modular and allows you to pick the OTA which means you choose aperture, you choose focal-ratio, you choose the focuser. This gives a lot more freedom on which camera(s) are ideal for your setup, and of course, which overall scope you want to use. Visually they're good, especially for looking at large structures in higher resolution as this is the least expensive way to get larger apertures (and 70~102mm apertures in solar is actually very big). Yes, they require power and time to warm up to temp to be on band. About 5~7 minutes usually. Imaging wise, the Quark is a gateway choice to high resolution imaging if your seeing conditions support larger apertures. Imaging with an 80mm, 102mm or 120mm for example is a very different output than something only 60mm. So if your interest is single large structures highly magnified and higher resolution, this is an option that outpaces smaller apertures for this price point. Compromises will be that imaging a full disc with a Quark is very difficult, requires compromises to achieve due to the focal length (Quark's have an internal 4.3x telecentric amplifier, so you're always working with long effective focal length, which makes full disc imaging hard). This would require multiple OTAs to control FOV, such as a very tiny short OTA for full disc viewing/imaging and still requires focal reducers and spacers to accomplish that, with an effective 12mm aperture blocking filter, so larger sensors can be used (which is good for flexibility). And another OTA with larger aperture (and a really good focuser) to do high resolution or simply larger magnification views of the partial disc, with significantly longer focal-lengths. The other big compromise is that there's no commercial way to double-stack this without getting another HA filter of some kind and working it into the imaging train while maintaining aperture (the common way to double stack would be to have a dedicated HA telescope and use the Quark with it, effectively double stacking, so like the 60mm or 90mm options out there). There's also of course a few people who have used two Quarks together (one being the Combo version without the 4.3x telecentric internally) with passable results, but I don't suggest this at all really. The Quark really should be looked at as a single stack solution with higher resolution options due to being able to use larger apertures right away. This can be good for imaging. Visually it can be good, but since its single stack it will be lower contrast. There's always compromise in some way.

 

Personally, I vastly prefer visual of the sun with a double stack and smaller aperture, I like seeing the whole disc and all the features at once with high contrast. So for me, I much prefer to use my 60mm double stack visually than my larger scopes. I have larger scopes ranging from 80mm to 200mm in HA that are single stacks and I image high resolution often. But visually they're not as appealing with less contrast. So this is again greatly personal preference, someone else may prefer totally different options. But having a 200mm solar scope and all options below that, visually I frankly prefer to do visual with a smaller double stack. The contrast is the king for me. Imaging, I like full discs, but I also really like moderate aperture for resolution, so I like being in that 120mm aperture range for imaging and my seeing supports larger apertures fairly common here in Florida in the mornings.

 

So again, food for thought and take it with a grain of salt. It all comes down to what you want the most out of what you're looking to get into and what your expectations are.

 

Very best,

A whole lot to unpack there. Thanks for the detailed response.

 

It seems like one way to go for me would be to go with a double-stacked Lunt 50mm for primarily visual use, while saving up for something like a quark chromosphere to get for dedicated imaging.

 

Do you have a lot of experience with the quark? I have some concern about its longevity since it uses electronic components -- altogether my impression of it from my armchair is that it may be a bit finicky, but the prospect of imaging with long focal length lenses is very attractive (seeing permitting).



#13 MalVeauX

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Posted 30 May 2020 - 10:02 AM

A whole lot to unpack there. Thanks for the detailed response.

 

It seems like one way to go for me would be to go with a double-stacked Lunt 50mm for primarily visual use, while saving up for something like a quark chromosphere to get for dedicated imaging.

 

Do you have a lot of experience with the quark? I have some concern about its longevity since it uses electronic components -- altogether my impression of it from my armchair is that it may be a bit finicky, but the prospect of imaging with long focal length lenses is very attractive (seeing permitting).

I have extensive experience with Quarks. But its anecdotal. Quarks are still an entry device. The longevity is fine, you won't find any sort of correlatable data of Quarks not lasting for a while. Instead, getting into a Quark is a gamble for uniformity and finesse of the etalon itself in quality. They're not all equal. Again, its an entry device. The same is true of the Lunt 50. The big difference is of course potential resolution due to aperture differences in configuration options. And the other big difference is, Lunt will readily support their product here in the USA and generally is reasonable. Daystar has support here in the USA too, but it's rarely inexpensive (no single component on a Quark if needed repair is inexpensive, nearly more cost effective to simply buy another Quark). An etalon from either can end up decontacted. There's no perfect solution of perfect magic bullet purchase. Everything has some compromise in some fashion.

 

You're better off figuring out if you want to do visual mostly, or imaging mostly (its very hard to do both, because if you're doing visual and want to image, well, you can't do visual while imaging other than electronically viewing while imaging... etc). If your goal is to let friends/family look at our star rapidly, with less gear, visual is easier. For imaging, you need a computer, camera, etc going around with you. More batteries. More stuff to fiddle with. And honestly there's a big difference between seeing it in an eyepiece and seeing it on a laptop screen. So you really have to decide what you think its more appealing. A Lunt 50 will work from a camera tripod, no motors, and be grab & go friendly. A Quark allows for instant binoviewing with bigger apertures, which is hugely appealing for structures on the limb. Two very different experiences honestly.

 

I would not get a Lunt 50 and then a Quark honestly, getting two entry devices for different purposes. For the same money you put in that, you could have had a good double stacked 60mm system. It's hard to make these choices without having experienced any of it to figure out your preference.

 

It would really be in your best interest to go to a local club or something to see different solar options and physically view through them to see what's most appealing for you. A blind purchase is really hard in this because there's so much compromise on the entry devices.

 

Very best,


Edited by MalVeauX, 30 May 2020 - 10:09 AM.

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#14 RickV

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Posted 30 May 2020 - 10:09 AM

Marty pretty much hit the nail on the head... excellent advice!

 

Me?  I owned a Lunt LS50 Pressure Tuned.  I used it mainly for imaging and struggled with it's poor helical focuser... replaced it with four different units - looking for no slop.  But I was disappointed in the LS50 imaging performance verses others posting here with LS60 - tilt tuned (was way better).

To me, hanging a double stack unit on the front of the Lunt 50 so/so etalon is not way I would proceed.  Pretty ears on a dog.

 

If you want commercial/out of the box/ ready to go, I'd be looking a 60mm DS unit.

 

I dumped my LS50 and bought a Quark Chromosphere and put it on a 50mm scope.  Immediately I could details that were just not there with the LS50 - better resolution.  After a year, just now in fact, I just added a Lunt LS50C (double stack unit) to the front of my 50mm scope.  (DS unit, scope, Quark).  Very nice performance... but I had the technical hands/on skills to cobble it all together.

 

I hope that helps.

 

Best,

Rick


Edited by RickV, 30 May 2020 - 10:12 AM.

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#15 Bokchoy Ninja

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Posted 30 May 2020 - 10:58 AM

I have extensive experience with Quarks. But its anecdotal. Quarks are still an entry device. The longevity is fine, you won't find any sort of correlatable data of Quarks not lasting for a while. Instead, getting into a Quark is a gamble for uniformity and finesse of the etalon itself in quality. They're not all equal. Again, its an entry device. The same is true of the Lunt 50. The big difference is of course potential resolution due to aperture differences in configuration options. And the other big difference is, Lunt will readily support their product here in the USA and generally is reasonable. Daystar has support here in the USA too, but it's rarely inexpensive (no single component on a Quark if needed repair is inexpensive, nearly more cost effective to simply buy another Quark). An etalon from either can end up decontacted. There's no perfect solution of perfect magic bullet purchase. Everything has some compromise in some fashion.

 

You're better off figuring out if you want to do visual mostly, or imaging mostly (its very hard to do both, because if you're doing visual and want to image, well, you can't do visual while imaging other than electronically viewing while imaging... etc). If your goal is to let friends/family look at our star rapidly, with less gear, visual is easier. For imaging, you need a computer, camera, etc going around with you. More batteries. More stuff to fiddle with. And honestly there's a big difference between seeing it in an eyepiece and seeing it on a laptop screen. So you really have to decide what you think its more appealing. A Lunt 50 will work from a camera tripod, no motors, and be grab & go friendly. A Quark allows for instant binoviewing with bigger apertures, which is hugely appealing for structures on the limb. Two very different experiences honestly.

 

I would not get a Lunt 50 and then a Quark honestly, getting two entry devices for different purposes. For the same money you put in that, you could have had a good double stacked 60mm system. It's hard to make these choices without having experienced any of it to figure out your preference.

 

It would really be in your best interest to go to a local club or something to see different solar options and physically view through them to see what's most appealing for you. A blind purchase is really hard in this because there's so much compromise on the entry devices.

 

Very best,

That's a very fair set of points.

 

I would definitely consider going with a Lunt 60mm SS except for the fact that it's no longer made by Lunt and not available on any of the classifieds. In addition I'm a pretty impatient guy, haha.

 

I also question the maths, as you mentioned going from 50mm to 60mm means a resolution jump of 20%, so I question whether that 20% boost is worth paying a 100% cost increase. I see what you mean about easier usage for imaging, however, which is certainly worth something.

 

I don't know why both Lunt and Meade decided to discontinue their 60mm models, aside from just forcing consumers to pay even more for the 70/80mm models, but it's a bit frustrating.



#16 MalVeauX

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Posted 30 May 2020 - 11:17 AM

That's a very fair set of points.

 

I would definitely consider going with a Lunt 60mm SS except for the fact that it's no longer made by Lunt and not available on any of the classifieds. In addition I'm a pretty impatient guy, haha.

 

I also question the maths, as you mentioned going from 50mm to 60mm means a resolution jump of 20%, so I question whether that 20% boost is worth paying a 100% cost increase. I see what you mean about easier usage for imaging, however, which is certainly worth something.

 

I don't know why both Lunt and Meade decided to discontinue their 60mm models, aside from just forcing consumers to pay even more for the 70/80mm models, but it's a bit frustrating.

Keep in mind that Lunt is using ED optics in their modular refractors, unlike Coronado. That's a big deal. That means when you use the modular Lunt refractor, you're going to have less false color so its actually useful for nighttime and daytime RGB imaging.

 

https://luntsolarsys...pe/lunt-ls60mt/

 

It's a little over budget. But, you could get the complete 60mm modular scope that lets you use it as HA, or any wavelength, its an ED doublet at its heart, with a 6mm blocking filter (which is fine for that focal length). And in the future you could put a double stack module on it when and if you have the interest to do so.

 

Alternatively, patience.... they come up used here and there. A rash of 60mm scopes were just posted and sold just a few weeks ago. You're not missing anything right now. It's the solar minimum, so its not like you're missing the big show that will happen in the next 4~6 years (and it will be near impossible to buy these things during that time as the demand will go through the roof).

 

As for the difference of 20%, 25% and 50% resolution increases, being 100% or more expensive.... yes it matters a lot if you're imaging primarily. The difference in resolution from 40mm and 50mm to a 60mm is significantly different in imaging and it shows readily in images. You can look at examples all day around here or with image searches. Visually you can still be very pleased with a 40mm view. But imaging it makes a rather big difference to get as much aperture as you can get.

 

Very best,


Edited by MalVeauX, 30 May 2020 - 11:26 AM.


#17 Gregory Gross

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Posted 30 May 2020 - 11:50 AM

I also question the maths, as you mentioned going from 50mm to 60mm means a resolution jump of 20%, so I question whether that 20% boost is worth paying a 100% cost increase.

For H-alpha solar observing, I think it's important to set aside some of the lessons we learn from using telescopes at night, namely the notion that aperture is king. To be sure, aperture is important for light gathering and resolution whether the application is daytime or nighttime astronomy. But for H-alpha solar work, the quality of the etalon is key. Keep in mind that most of what you're paying for in terms of the price difference between the 50 and 60mm Lunt is a better etalon, which is far and away the most expensive part of any H-alpha solar scope. A better etalon will offer a wider tuned sweet spot. I found that my 50mm Lunt's sweet spot was just a tad short of covering the entire disk of the Sun. That said, that little scope punched way above its weight and offered a very satisfying observing experience.

 

I see that the price for an LS50THa with 6mm blocking filter is the very same as the LS50C double stack module that fits onto the LS50THa (both are $849). One of the reasons why internal etalons exist is because there is a cost savings to making the etalon smaller. Since internal etalons are placed further back along the cone of light, they can be made smaller and thus cheaper than larger front-mounted etalons, which can offer better performance for various reasons.

 

In addition to my lengthy comments here about my experience owning a double-stacked Lunt in both their 50 and 60mm configurations, I'd underscore my belief that double stacking any H-alpha scope is more than worth the expense of doing so for visual use. There is simply no comparison between the single- and double-stacked observing experience. I distinctly remember the first time looking through my 50mm Lunt with its double stack module after having first owned and used the scope in single stack mode for six months. It was like I had a wholly different piece of gear.

 

I try very hard to make the most of the money that I put into my hobby. When I was new to H-alpha solar observing, I was reluctant to plow a lot of money into an area that is notoriously expensive and that I was unfamiliar with. I took it easy at first: I bought an LS50THa and used it just as it came out of the box for a while. Later as I saw my excitement for H-alpha grow, I added a better focuser, invested in a Lunt zoom eyepiece, and finally got a double-stack module. Each step triggered a new level of enthusiasm for this little niche within a niche in the overall amateur astronomy hobby.

 

What I'm driving at is that that little 50mm Lunt I had for a few years opened myself up to an enduring passion for solar astronomy, a passion that eclipsed (pun intended) my interest in nighttime observing. So it was very much money well spent.


Edited by Gregory Gross, 30 May 2020 - 11:59 AM.

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#18 MalVeauX

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Posted 30 May 2020 - 12:00 PM

I'd underscore my belief that double stacking any H-alpha scope is more than worth the expense of doing so for visual use. There is simply no comparison between the single- and double-stacked observing experience.

I will second this, it's such a drastic difference. I have single stacks from 40mm to 200mm and none of them, no matter how big my aperture is (and my seeing supporting it), none of it compares to a really good double stack view. The contrast is unreal and you see an image that is just insane. A single stack is certainly a great toe in the water to get a taste. But man, the double stack, a well tuned double stack with a big sweet spot is just so crazy to look at. As much as I'm an imager mostly for this, I put a lot of effort into my preferred visual scope which is a double stack with front mounted etalons for this reason. For a visual approach, having a double stack as an option is a big deal and I would take a smaller aperture double stack over a large single stack for visual use any day (unless planning to double stack it later, end result being, a double stack regardless). My favorite single stack is a 120mm aperture, and it's just great for prominences and the limb. But even then, I just still prefer the punchy high contrast of my 60mm double stack for a visual experience. Plus, its not a big affair to enjoy it unlike my 120 which needs a huge mount.

 

Very best,


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#19 Bokchoy Ninja

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Posted 30 May 2020 - 12:04 PM

For H-alpha solar observing, I think it's important to set aside some of the lessons we learn from using telescopes at night, namely the notion that aperture is king. To be sure, aperture is important for light gathering and resolution whether the application is daytime or nighttime astronomy. But for H-alpha solar work, the quality of the etalon is key. Keep in mind that most of what you're paying for in terms of the price difference between the 50 and 60mm Lunt is a better etalon, which is far and away the most expensive part of any H-alpha solar scope. A better etalon will offer a wider tuned sweet spot. I found that my 50mm Lunt's sweet spot was just a tad short of covering the entire disk of the Sun. That said, that little scope punched way above its weight and offered a very satisfying observing experience.

 

I see that the price for an LS50THa with 6mm blocking filter is the very same as the LS50C double stack module that fits onto the LS50THa (both are $849). One of the reasons why internal etalons exist is because there is a cost savings to making the etalon smaller. Since internal etalons are placed further back along the cone of light, they can be made smaller and thus cheaper than larger front-mounted etalons, which can offer better performance for various reasons.

 

In addition to my lengthy comments here about my experience owning a double-stacked Lunt in both their 50 and 60mm configurations, I'd underscore my belief that double stacking any H-alpha scope is more than worth the expense of doing so for visual use. There is simply no comparison between the single- and double-stacked observing experience. I distinctly remember the first time looking through my 50mm Lunt with its double stack module after having first owned and used the scope in single stack mode for six months. It was like I had a wholly different piece of gear.

 

I try very hard to make the most of the money that I put into my hobby. When I was new to H-alpha solar observing, I was reluctant to plow a lot of money into an area that is notoriously expensive and that I was unfamiliar with. I took it easy at first: I bought an LS50THa and used it just as it came out of the box for a while. Later as I saw my excitement for H-alpha grow, I added a better focuser, invested in a Lunt zoom eyepiece, and finally got a double-stack module. Each step triggered up a new level of enthusiasm for this little niche within a niche in the overall amateur astronomy hobby.

 

What I'm driving at is that that little 50mm Lunt I had for a few years opened myself up to an enduring passion for solar astronomy, a passion that eclipsed (pun intended) my interest in nighttime observing. So it was very much money well spent.

Thanks for your reply. I also read your other post which was helpful.

 

I think I'm going to go with the double stacked Lunt 50mm. Despite the warnings of "skip the intermediate steps," I think it's important to keep in mind that a large number of people will be happy with what they purchase and feel no need to upgrade. Starting at "beginner" instruments may be a good strategy for most, similar to buying a $200 yamaha acoustic before splurging on a $5,000 custom american guitar if you're just getting your feet wet.

 

The 50mm may not easily accommodate my desire to get into solar imaging, but I've seen examples of people doing this successfully and I don't mind tinkering.


Edited by Bokchoy Ninja, 30 May 2020 - 12:05 PM.

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#20 Gregory Gross

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Posted 30 May 2020 - 12:38 PM

Not to suggest that you should be planning to sell the scope you don't already own yet, but one thing you might consider is searching CN classifieds or Astromart for any 50mm Lunts that have sold. Establishing the market rate for a scope you have your eye on purchasing may give you a better sense of confidence about how well it will retain its value. Knowing that you have the later option to sell and upgrade with relative ease can make one more comfortable with making a big purchase especially in an unfamiliar area. Lunt also offers a trade-in program.

 

I also think there's something to be said about the value of getting your hands on something -- anything -- that will give you the opportunity to become more familiar with a new area. And H-alpha solar astronomy is very much unlike nighttime astronomy. For one thing, solar scopes have their own quirks that are different than those which characterize nighttime gear. What's more, the object of study -- the Sun -- is constantly changing, and there's always something new to discover every day the Sun is shining in the sky. M42, M13, etc. are all beautiful, but they're the same M42 and M13 year in and year out. Day by day and even hour by hour, the Sun is changing, and there's always something new to observe even during periods of solar minimum. H-alpha observing really is its own exciting thing.

 

And one more thought: Lunt is a really solid small company to work with, and their customer service is first rate. Dealing directly with them by purchasing on their website is one great way to support them and to establish a customer relationship with the company.



#21 George9

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Posted 30 May 2020 - 09:33 PM

Bokchoy Ninja, there is excellent advice above. I think with a limited budget, you really need to pick either visual or imaging and pursue that one primarily, still doing a little of the other.

 

For visual, you ideally want a double stack and a binoviewer. I have liked the two LS50 DS's I have looked through, but I have not tried to binoview them. (For someone who knows he or she only wants prominences, then a Quark and a binoviewer on a range of refractors makes the most sense on a budget. I would not limit myself to prominences, though. The Quark does best on the disk when seeing is great, or when you are on a smaller scope, or when you happen to have gotten a more narrowband Quark.)

 

For imaging, the above advice is great.

 

George



#22 George9

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Posted 30 May 2020 - 09:54 PM

As much as I'm an imager mostly for this, I put a lot of effort into my preferred visual scope which is a double stack with front mounted etalons for this reason. For a visual approach, having a double stack as an option is a big deal and I would take a smaller aperture double stack over a large single stack for visual use any day (unless planning to double stack it later, end result being, a double stack regardless). My favorite single stack is a 120mm aperture, and it's just great for prominences and the limb. But even then, I just still prefer the punchy high contrast of my 60mm double stack for a visual experience. Plus, its not a big affair to enjoy it unlike my 120 which needs a huge mount.

Marty, I know most of your energy goes into imaging, but why not go for a large double stack? Not only is it fun visually, but it is possible that you might see things in the large scope that would influence how you process your images (unless of course you have already done a lot of large aperture double stack in the past). E.g., on a day of great seeing, it is surprising what a flare and the surrounding structures look like.

 

It used to be hard to double stack large, but now with a Quark and a DSII unit, it just works. The sweet spot is a little small (maybe half the maximum field of view) and a little darker than I like, but still amazing. I have heard many comments from experienced H-alpha observers who were blow away by the first view through a large double stack. You may even already have all the parts to put one together (Quark and PST etalon?), but you would need to figure out the transfer lenses. 

 

I am still working on my C11 double stack, so I won't yet make a recommendation on your 8". So far I can get the same view as my 6" refractor, but I have not had the seeing to do better, and I have not yet figured out the optics spacing (I need good enough seeing to tell if I am improving the view).

 

George



#23 MalVeauX

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Posted 30 May 2020 - 10:02 PM

Marty, I know most of your energy goes into imaging, but why not go for a large double stack? Not only is it fun visually, but it is possible that you might see things in the large scope that would influence how you process your images (unless of course you have already done a lot of large aperture double stack in the past). E.g., on a day of great seeing, it is surprising what a flare and the surrounding structures look like.

 

It used to be hard to double stack large, but now with a Quark and a DSII unit, it just works. The sweet spot is a little small (maybe half the maximum field of view) and a little darker than I like, but still amazing. I have heard many comments from experienced H-alpha observers who were blow away by the first view through a large double stack. You may even already have all the parts to put one together (Quark and PST etalon?), but you would need to figure out the transfer lenses. 

 

I am still working on my C11 double stack, so I won't yet make a recommendation on your 8". So far I can get the same view as my 6" refractor, but I have not had the seeing to do better, and I have not yet figured out the optics spacing (I need good enough seeing to tell if I am improving the view).

 

George

Hey George,

 

I would adore having a larger double stack that is bright with a huge sweet spot! I have used larger double stacks and still have everything, (my 200mm F10 was (and can still be) double stacked for a while with two of the etalons you mentioned and the full aperture D-ERF), but the issue is several things, economic, unfortunately as well as I find that the FOV of a high res system is not what I prefer visually, as I like to see the whole structure and many AR's, proms, etc, are much larger than a tiny FOV coming from a large 8+ inch scope and its little sweet spot from the etalon(s) (since longer and longer you go, the smaller that sweet spot gets). It's also an issue of seeing; my seeing is great for imaging, but lucky imaging can do wonders compared to what visual is like. I simply don't really care to go larger than about 100mm visually even though I have 120mm, 150mm and 200mm solar scopes. 200mm's FOV (Quark) was simply too narrow. The limb was crazy. But, I much preferred the wider FOV of the 150mm. And in turn, preferred the 120mm. I find 120mm to be the sweet spot for me in general for my preference and seeing conditions as a limiter at any given time of day (not just the best time of day). Getting better etalons is simply too expensive for me still (otherwise, I'd have a Quantum and a 1A blocking filter ideally). Putting together a 80~100mm double stack is significantly expensive, even used and pieced together and even more rarely sold used compared to smaller items. My ideal `practical' scope at this point is actually a 90mm double stack with external etalons for visual and can image with it all day with my seeing conditions.

 

That said, I really don't need a 2nd etalon, just a good primary that can bused modularly. I'm actually waiting for a better blocking filter. They're available, just custom orders of course and costly. A single good etalon can do the job for getting most of the filtration done. I'm waiting for a hard coated 1 angstrom blocking filter (around 8~10mm diameter). It would be cheaper than a large etalon, but more expensive than most blocking filters are of course, but it's enough to trim the skirt of the transmission profile and with a single good etalon with high finesse will produce what normally takes two etalons and a blocking filter to produce.

 

Very best,


Edited by MalVeauX, 30 May 2020 - 10:12 PM.

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#24 George9

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Posted 31 May 2020 - 07:12 AM

Very good. Thanks for the very informative reply. Yes, now I use a Solar Spectrum RG32 0.3A as one of the filters, and that widened the view and brightened the image so that I am near the full view in a 24mm Pan (80-90%), and still bright enough to binoview and add a 1.7x multiplier (on top of the TZ4, so over 300x). I can get about a third of the Sun binoviewed in the 6" (up to half cyclops). The cost is definitely high but at least not ridiculous (similar to an LS80 DSII with FT and B1800, so not that different from what many invest in solar). By the way, an RG46 0.5A would show even more.

 

I like your idea of the 1A hard filter. I tried a 2A hard filter (taken out of an old prominence filter) and was very disappointed. Dark, and really no improved contrast. I expected at least some improvement, and the calculations showed it should have worked. Maybe it is not really 2A. So instead I treat the DSII unit effectively as another blocking filter, and the cost is similar to a large blocking filter.

 

I agree with the 90mm front double stack being ideal (with my LS80 DSII with circular polarizer etc. being similar).

 

George


Edited by George9, 31 May 2020 - 07:26 AM.

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#25 Bokchoy Ninja

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Posted 31 May 2020 - 01:00 PM

Ok quick question. I'm gonna go for a Lunt 60 afterall.

For visual and imaging, does it matter whether I go with pressure tuning or tilt tuning? I want to make sure I'm putting my money into the most effective features


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