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Ha Solar Scopes/Solar Filters

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#26 Eddgie

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Posted 11 October 2014 - 08:12 AM

Out of the box, I had to adjust the pre-load on the two speed focuser, but this is pretty much the same as with my SV 110ED, which appears to use the same focuser, though it has the ability to rotate, and the Lunt one does not.

 

Anyway, I have not had any issues with using the focuser with the binoviewer, but the Maxbright is super-light, and Ionly use a single pair of eyepeices (Vixen NPL Plossls) for 100% of my Ha observing.  I find that this magnification gives the best balance between full disk, prominances, and surface detail (the Lunt 60 can't really resolve detail in the penumbra of sunspots when tuned off band, so going higher does not bring out any new detail in these features). 

With the 15mm Plossls, I get about 50x I think?  Something like this.

 

Anyway, the focuser has not given me any problems but again, I did have to slightly tighten the preload on the two speed unit, but mostly that was when I was trying out Baader Zoom eyepecies (heavy.. Did not like using them in this scope.. Could not use winged eyeguards).

 

Remember, you have to use a GPC.  I am using a 1.25x GPC mounted in front of the BF-1200.   I did a post about 7 or 8 months ago on the binoviewer forum on how to do this.

 

You can also use a bigger GPC in the normal location of course, and there are other ways to get there, but for me, the Maxbright is dedicated to this scope, and part of the reason I like this configuration is because it does indeed reduce the load on the focuser by having it directly mounted the same way that it would mount to a T2 diagonal.

 

The BF-1200 is of course T2 already, so the Maxbright just screws on.  But you need one adapter to mount the GPC in front of the BF the way I did it.  PM me if you have any questions.


Edited by Eddgie, 11 October 2014 - 08:25 AM.


#27 City Kid

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Posted 11 October 2014 - 08:45 AM

 I'm not going to spend hours staring at it, day after day.....

You might be surprised. I recently got a Lunt Ha filter for my refractor and I spend way more time observing the sun than I ever thought I would. In fact I'm getting ready to set up my stuff in about 30 minutes or so and I'll probably leave it set up the rest of the day taking peeks here and there throughout the day. One of the things that makes it so cool is the view is constantly changing. The view I have an hour from now will be different than the view later in the day. I can't hardly get my wife to spend 5 minutes at the eyepiece in my scopes at night but she will spend long periods of time looking at the sun in Ha.



#28 WebFoot

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Posted 21 October 2014 - 10:53 AM

So, I've been grazing in the classifieds here and on Astromart, and what I think is best for me hasn't come up.  And the discount from new isn't compelling for what has come up.

 

While I (like most of us) have aperture fever, and would love an 80, 90 or 100mm system, I'm not willing to pay for it (and the Coronado appears to have a horrible focuser).  I'm willing to pay for a 60mm Lunt, with all the trimmings.  But I have some questions:

 

1.  Will a 60mm scope allow for decent photos, either with an SBIG ST-8XE, or with a DSLR (either full frame or APS-C; I have both)?

2.  Does pressure tuning make a significant difference?

3.  Does double stacking make a significant difference?

 

Thanks.

 

Mark



#29 bandazar

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Posted 22 October 2014 - 04:56 PM

Kind of surprised nobody has responded yet.

1.  can't answer that

2. In terms of detail no, in terms of seeing the whole entire sun without a sweet spot issue, yes.  If you're going to be doing astrophotography I'd go with pressure tuning, probably..

3.  Depends on way too many factors.  You can do a search on this group to find out though.  IMO, in small apertures it is generally not worth it.  But I know other people will disagree with me on this.  It just comes down to personal preference.  In large/medium apertures it might be worth it depending on what you like to see on the sun and how good a "fit" the double stack is to the original scope.



#30 BYoesle

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Posted 23 October 2014 - 06:19 AM

I'm not going to spend hours staring at it, day after day

 

 

Want to bet?  Come visit me on a sunny day.

 

 

I can't hardly get my wife to spend 5 minutes at the eyepiece in my scopes at night but she will spend long periods of time looking at the sun in Ha.

 

'nuff said.

 

 

So, I've been grazing in the classifieds here and on Astromart, and what I think is best for me hasn't come up.

 

Right now there is an incredible deal on a pre-Meade Coronado (i.e. Lunt Tucson) SM90 double stacked scope on AM: http://www.astromart...ified_id=869619  This scope appears to have an improved focuser, and would likely kill any other scope out there of similar aperture.  If you don't have the cash take out a loan and buy it for heavens sake!

 

1.  The SBIG and DSLR will not be as good for solar imaging as a cheaper video camera based system using multiple frame stacking and alignment, as is done in lunar and planetary imaging.  The DSLR in particular will be poor due to the Bayer layer giving only 1/2 the sensors resolution and 1/4 of the sensitivity.

 

2.  Yes, pressure tuning is the better way to go with an internal etalon for optimum uniform contrast performance, especially for full disk views/imaging:

 

Attached File  Full Disk enh jpg SM.jpg   194.58KB   5 downloads

 

3.  Double staking makes an incredible difference in contrast and detail regardless of aperture, not only decreasing the FWHM to ~ 0.5 A, but moreover by reducing the continuum light leaking through the tails of the filters transmission curve:

 

Attached File  Single v double etalon-0.7 v 0.45 A compare jpg sm.jpg   287.2KB   9 downloads

 

The identically processed images above clearly shows the continuum leakage through a 0.7 A FWHM filter via the "double limb" of the photosphere; note the sunspot detail is more visible from the photosphere as well.  Double stacking will however reduce image brightness, which can be mitigated via shielding, etc.  For additional see: http://www.cloudynig...s-double-stack/  , http://www.cloudynig...l/#entry5656244


Edited by BYoesle, 23 October 2014 - 07:57 AM.


#31 Eddgie

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Posted 23 October 2014 - 10:34 PM

So, I've been grazing in the classifieds here and on Astromart, and what I think is best for me hasn't come up.  And the discount from new isn't compelling for what has come up.

 

While I (like most of us) have aperture fever, and would love an 80, 90 or 100mm system, I'm not willing to pay for it (and the Coronado appears to have a horrible focuser).  I'm willing to pay for a 60mm Lunt, with all the trimmings.  But I have some questions:

 

1.  Will a 60mm scope allow for decent photos, either with an SBIG ST-8XE, or with a DSLR (either full frame or APS-C; I have both)?

2.  Does pressure tuning make a significant difference?

3.  Does double stacking make a significant difference?

 

Thanks.

 

Mark

 

I had read and been told that the "Sweet spot" would be bigger on a pressure tuned unit, and I am not at all positive that this is the case.  I still have sweet spot issues with the pressure tuner.   I asked the people at Lunt about this and they said that every effort is made to optimize the field at peak tuning, but I find that there are still tuning positions where you simply don't get filament detail on the whole full disk.

 

Also, the pressure tuner is kind of stiff.  Mine is 7 months old, and I use it a lot, and while it has smooted out a bit, I could not see using this on a light Alt-az mount.   On a Vixen Porta II, tuning took so much twisting effort that the entire scope and tripod would flex around like crazy on my little mount.  I had to move the scope to a Polaris to keep if from shaking around when I tune.

 

I love the view, and overall, I am very happy with the Lunt 60, but it is not a "Perfect" as I had expected, and considering the price and the tuning issue, sometimes I think I should have bought the tilt tuned version. 

 

I have talked to a few other people that have looked through both and some report a bigger sweet spot in the pressure tuner, but I know one other person that has had the same experience I had.

 

Lunt did say that they would look at my scope, but said that the condition I was experiencing was normal, and that it was almost impossible to make the scope work perfectly across the full disk at all tuning levels.



#32 WebFoot

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Posted 23 October 2014 - 11:31 PM

Right now there is an incredible deal on a pre-Meade Coronado (i.e. Lunt Tucson) SM90 double stacked scope on AM: http://www.astromart...ified_id=869619  This scope appears to have an improved focuser, and would likely kill any other scope out there of similar aperture.  If you don't have the cash take out a loan and buy it for heavens sake!

 

Thanks for the shove.  I had been eyeing three scopes for sale:  A 100mm Lunt, and two 90mm Coronados.  The Lunt is too expensive for what it comes with, with no sign that the seller is interested in dropping the price; I couldn't get comfortable with the older Coronado, but I did get comfortable with the newer Coronado 90 double-stacked.  We have a deal, and I've paid.  Hopefully, it gets shipped tomorrow, and sometime this winter, Seattle's perma-cloud layer will lift.

 

I have read that the focuser on the new Coronados is shoddy, but solutions exist, so I can fix it if it's not acceptable, and can get a larger blocking filter if I feel the need.  

 

90mm is a lot more than 60; I hope it's worth the risk of buying used from an unknown party!

 

Mark


Edited by WebFoot, 23 October 2014 - 11:32 PM.


#33 bill1234

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Posted 24 October 2014 - 08:36 AM

Glad to see you finly pulled the triger on a purchase :) You have come a long way since starting this thred.I am shore going big  cost you more now , but it will save you regret later...guarenteed



#34 germana1

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Posted 24 October 2014 - 08:26 PM

Your going to really like it, me going from a 40 to 90 made a big difference!

pete



#35 bobmarleyou812

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Posted 26 October 2014 - 02:45 PM

I thank you all for your input.  Both the better Coronado and the Lunt offerings look nice.  But I have difficulty figuring out why I would be better off paying for another scope, with optics inferior to my Taks.  Is it the case that daytime viewing does not favor excellent optics?

I was in a similar situation.  I have a TV85 that I'm extremely happy with.  I wanted to get a Ha filter for the front of the TV85, but by the time you buy the filter, the BF, and the adapter, you may as well have a dedicated instrument.  I ended up snagging a used Lunt 60PT.  The Lunt takes some getting used to, as far as tuning, focusing, and centering in the eyepiece.  But it is far superior to the PST I used to own.  I can mount the Lunt and TV85 w a white light filter side-by-side and have the best of both worlds.  Attached File  IMAG0100 (579x1024).jpg   397.09KB   5 downloads



#36 gatorengineer

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Posted 26 October 2014 - 07:02 PM

Late to the party, but the Quark on the FSQ is simply amazing.  A full aperature wratten red photo filter for $60 from Fleabay for the ERF.....  Very very satisfied, and can get most of a whole disk, great for outreach.....  in my opinion slightly over a grand very well spent



#37 WebFoot

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Posted 29 October 2014 - 03:36 PM

The Coronado arrived today, and the astronomy gods were with me--even Seattle had a bit of sunshine.  It works well, it seems, although there certainly will be a learning curve involved in getting the most out of it (and a longer learning curve, I suspect, when I decide to start imaging with it).

 

One nice flare, at about 135 degrees in the eyepieces, and a number of tiny ones around the edge.

 

Thanks for all your help; it is most appreciated!

 

Mark



#38 C8er

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Posted 29 October 2014 - 03:57 PM

My Chromosphere model Quark shows both proms and surface features perfectly well in the same view, both for visual and imaging.

 

Cheers,

Chris M

 

 

For the cost you might just want to consider the PST or the 50 mm Lunt so you can see both the surface features (flares, filaments, etc) and prominences.  Reading the Daystar website (if I understand it correctly) you buy either or and if you want to look at both then you are in the same price range of a nice sized solar scope.








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