Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

5 Angstrom Solar Filter

  • Please log in to reply
25 replies to this topic

#1 briansalomon1

briansalomon1

    Vostok 1

  • *****
  • topic starter
  • Posts: 145
  • Joined: 21 Jul 2018
  • Loc: Oxnard CA

Posted 13 February 2020 - 01:49 PM

I've always wanted a 5 Angstrom solar filter (or telescope) but could only afford the neutral density type in the past.

 

I'm seriously considering one now and have been searching for advice on this and thought someone here would have experience.

 

I've been looking at the Coronado Solarmax III. I like being able to add a second filter for a lower wavelength filter.

 

I also like that that model needs no electricity.

 

I have a Televue Oracle III (76mm) and an NP101is (101mm) and my inclination is to just get the filters for one of these instead of buying a dedicated scope.

 

What do you guys like?



#2 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 19,551
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 13 February 2020 - 02:09 PM

I don't have an H-Alpha yet but my choice is a separate dedicated OTA.

Also, best to have the Mods move this to the Solar Forum.



#3 TOMDEY

TOMDEY

    Fly Me to the Moon

  • *****
  • Posts: 7,393
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 13 February 2020 - 02:42 PM

You mean 0.5 Angstrom, right? Ten times that will not show solar H-alpha stuff.    Tom


Edited by TOMDEY, 13 February 2020 - 02:43 PM.


#4 Jeff Struve

Jeff Struve

    Aurora

  • *****
  • Posts: 4,553
  • Joined: 05 Nov 2010
  • Loc: Iowa, USA

Posted 14 February 2020 - 09:33 AM

Other than buying something like a Quark... DayStar... I dont think you can just add filtering to a regular scope to do any more than white light type viewing/imaging... it takes a dedicated Ha solar scope.

 

I did compare my Lunt to a Daystar and thought that my Lunt was was crisper and had better contrast.



#5 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 19,551
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 14 February 2020 - 12:38 PM

Other than buying something like a Quark... DayStar... I dont think you can just add filtering to a regular scope to do any more than white light type viewing/imaging... it takes a dedicated Ha solar scope.

 

I did compare my Lunt to a Daystar and thought that my Lunt was was crisper and had better contrast.

I thought one could add this (with a proper custom adapter) on any smaller OTA (max says 1200mm, but usually 100mm F7 and smaller)



#6 Jeff Struve

Jeff Struve

    Aurora

  • *****
  • Posts: 4,553
  • Joined: 05 Nov 2010
  • Loc: Iowa, USA

Posted 14 February 2020 - 12:51 PM

I thought one could add this (with a proper custom adapter) on any smaller OTA (max says 1200mm, but usually 100mm F7 and smaller)

Looks like it... but kinda expensive as I think that I paid $1600 for my Lunt



#7 Volvonium

Volvonium

    Messenger

  • *****
  • Posts: 459
  • Joined: 06 Mar 2019
  • Loc: Long Beach, CA

Posted 14 February 2020 - 12:54 PM

I've always wanted a 5 Angstrom solar filter (or telescope) but could only afford the neutral density type in the past.

 

I'm seriously considering one now and have been searching for advice on this and thought someone here would have experience.

 

I've been looking at the Coronado Solarmax III. I like being able to add a second filter for a lower wavelength filter.

 

I also like that that model needs no electricity.

 

I have a Televue Oracle III (76mm) and an NP101is (101mm) and my inclination is to just get the filters for one of these instead of buying a dedicated scope.

 

What do you guys like?

 

I should be able to provide you with some feedback this weekend on the performance of a dual stacked dedicated solar scope (Pressure tuner in back, tilt tuner up front), vs a refractor using dual stacked tilt tuned etalons up front + blocking filter in the back.

 

Right now I'm running a Lunt 60mm f/8.3 LS60Tha Pressure Tune, for visual use only, with a 50mm double stack (LS50Fha) up front.  With the stopped down aperture of the 50mm double stack up front, I believe that would make the system an f/10.  Image is very pleasing, with many observable details, albeit I haven't been able to use too much magnification just yet; I would put my limited experience as an h-alpha observer and seeing conditions as being the predominant factor over the bottom line resolving power of the telescope.

 

I have a Televue 101 (TV-101) and will be trying a double stack of 50mm tilt tune etalons up front, and a B1800 blocking filter in the back.  It should be a worthwhile comparison-- The TV's Petzval design has a doublet up front, with another doublet corrector in the back.   The Lunt 60 pressure tuner has a singlet up front, with the internal pressure tuned etalon providing some kind of correction in the back.   Different optical designs, but not too dissimilar.  The TV101 with 50mm etalons up front would also be of a similar focal ratio at f/10.8...it should be an interesting and meaningful comparison.

 

 

I anticipate that with double stacked front etalons, the solar image might have some slightly perceptible banding, where the full disk may not be showing full detail like it would with the dedicated solar scope with pressure tuner.  I don't think it will be a deal breaker, on the other hand.   I like the versatility of using front etalons + blocking filter with other refractors.  It limits the amount of gear to bring out.  My hope is that using front etalons with the Televue refractor, with its good optics, will coax out some additional detail.

 

One thing with running front etalons + blocking filter + adapters on other refractors is that the whole system will wind up costing more than just buying a dedicated solar scope that is sold as a complete system.   


Edited by Volvonium, 14 February 2020 - 12:57 PM.


#8 Spikey131

Spikey131

    Surveyor 1

  • *****
  • Posts: 1,608
  • Joined: 07 Feb 2017

Posted 14 February 2020 - 01:21 PM

Your most economical route for a hydrogen alpha solar filter for using with your refractors is the Daystar Quark.  H alpha etalons (etalon = filter) need to be “tuned” and the Daystar method is to heat the etalon.  So you need electricity.  It is just a battery with a USB jack and a cord that you plug into the Quark, like you cell phone.  It takes about 10 minutes warm up.  You can get all set up for about $1300 new.  You need the Quark, battery, cord and a UV/IR blocking filter in front of you diagonal.

 

The other way to go is a front etalon and blocking filter.  I don’t know much about them except they are a lot more expensive.

 

I use a Quark with a TV 76 and NP101.  When setting up, the first thing I do is plug in the Quark.  By the time I set up the mount and the scope, the Quark is ready to go.  I am very satisfied with the Quark.

 

Whatever way you go, you can greatly enhance visual H alpha solar viewing with a binoviewer.


  • Volvonium likes this

#9 Volvonium

Volvonium

    Messenger

  • *****
  • Posts: 459
  • Joined: 06 Mar 2019
  • Loc: Long Beach, CA

Posted 14 February 2020 - 02:14 PM

I'm not terribly familiar with the Quark setups, but do those require setting up a front Energy Rejection Filter, and additional UV and IR blockers?

 

One of big draws for me regarding Lunt's offerings of either dedicated solar scopes or front mount etalons + blocking filters, is that they have redundant systems for blocking harmful UV and IR, should any component fail.  I believe they have UV and IR blocking integrated on the front ERF, the etalon itself, as well as within the blocking filters, greatly mitigating the risk if multiple component failure were to occur.

 

I would think one can build redundant safety features into a Quark setup as well, but I'm unsure of the costs involved.



#10 Spikey131

Spikey131

    Surveyor 1

  • *****
  • Posts: 1,608
  • Joined: 07 Feb 2017

Posted 14 February 2020 - 05:37 PM

The Quark does not require a front ERF on small scopes, I think smaller than 130mm aperture.

 

You don’t really need a UV/IR filter for visual use on non-tracking mounts in small scope, though I do use one.

 

It is inconceivable that the Quark could catastrophically fail and allow unfiltered light through.



#11 MalVeauX

MalVeauX

    Cosmos

  • *****
  • Posts: 7,650
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 14 February 2020 - 06:48 PM

I've always wanted a 5 Angstrom solar filter (or telescope) but could only afford the neutral density type in the past.

 

I'm seriously considering one now and have been searching for advice on this and thought someone here would have experience.

 

I've been looking at the Coronado Solarmax III. I like being able to add a second filter for a lower wavelength filter.

 

I also like that that model needs no electricity.

 

I have a Televue Oracle III (76mm) and an NP101is (101mm) and my inclination is to just get the filters for one of these instead of buying a dedicated scope.

 

What do you guys like?

Just to sort of re-orient things, bandpass largely doesn't matter, so don't chase a smaller and smaller number in that respect (ie, 0.7A, 0.5A, etc). Transmission profile and the ability to shave the skirt around it with a 2nd filter of some kind to remove the parasitic continuum is all that really matters in terms of that, along with uniformity and finesse of the filter. All of which are not measured, no standard, and you'll never know unless you evaluate it in person.

 

What's your budget?

 

Is the goal visual only, or do you plan on imaging?

 

Is your goal to have a double-stack system overall and is more important than aperture to you?

 

Very best,


Edited by MalVeauX, 14 February 2020 - 07:16 PM.


#12 Volvonium

Volvonium

    Messenger

  • *****
  • Posts: 459
  • Joined: 06 Mar 2019
  • Loc: Long Beach, CA

Posted 14 February 2020 - 07:24 PM

The Quark does not require a front ERF on small scopes, I think smaller than 130mm aperture.

 

You don’t really need a UV/IR filter for visual use on non-tracking mounts in small scope, though I do use one.

 

It is inconceivable that the Quark could catastrophically fail and allow unfiltered light through.

 

Interesting.  If the diagonal were to swing down and eyepiece were to fall out, there would be a potential issues of unfiltered, concentrated light being directed somewhere.   I've had diagonals swing down on me a couple times.   

 

Beyond unfiltered light, I would think that without any sort of robust ERF up front, the objective(s), diagonal, and other components downstream would be subject to a bit of thermal load/cycling that could damage components over time.  From what I understand, some of the issue with corroded blocking filters in Coronados and Lunts (down to their 35mm offerings) was related to this, when IR filtering was not part of the front ERF.  Better safe than sorry, IMO, but I concede that everyone has different risk tolerances.  With the Lunts, the part that tended to fail is replaced for free or end user replaced for a measly $8, which is much ado about nothing...but other makes have different configurations that might not be as simple to repair.


Edited by Volvonium, 14 February 2020 - 07:25 PM.


#13 briansalomon1

briansalomon1

    Vostok 1

  • *****
  • topic starter
  • Posts: 145
  • Joined: 21 Jul 2018
  • Loc: Oxnard CA

Posted 14 February 2020 - 09:06 PM

All great feedback. Right Tom, I did mean 0.5A.

 

As far as the budget goes I'm going to resist going over 4K.

 

I've always been a strictly visual observer.

 

I had assumed the quality of the telescope, at least the figure anyway, would affect the image in solar observing even with the narrow bandpass and thought the NP101 would be capable of a good image but if a dedicated scope works best then it's what I want.

 

Comparisons are hard to come by so I truly appreciate what experienced observers have to say. 



#14 MalVeauX

MalVeauX

    Cosmos

  • *****
  • Posts: 7,650
  • Joined: 25 Feb 2016
  • Loc: Florida

Posted 14 February 2020 - 09:13 PM

For 4K USD options that are double-stacks:

 

Solarmax II 90mm Etalon + Custom Adapter to mount onto NP101 + Daystar Quark Chromosphere + 10mm~15mm Blocking filter

 

Solarmax II 90mm Etalon x 2 + 10~15mm Blocking Filter + Custom Adapter to mount onto NP101

 

Lunt 60mm Front Mounted Etalon x 2 + Custom Adapter to mount onto NP101 and/or 76mm scope + 12~18mm Blocking Filter

 

Dedicated Lunt 80mm Double Stack (Pressure Tuned) + Blocking Filter (used overall)

 

I would push for something 80mm to 90mm in aperture, double stacked, for your budget. Dedicated scope or not, doesn't matter. Life time scope at that aperture.

 

Very best,


  • Volvonium likes this

#15 CarlDD

CarlDD

    Viking 1

  • *****
  • Posts: 742
  • Joined: 23 Jul 2007
  • Loc: Home is Serbia

Posted 15 February 2020 - 03:02 AM

Hi Brian

 

the Coronado SM90 threads onto the lens cell of the TV101 ( also NP101 ) see photo below of my setup. 

 

Upside is it provides superb views, especially when binoviewing.

Downside is it’s a heavy lump on the front end of the scope,  takes time to fettle for best view as you have two tilts and rich view rotation to sort out but once achieved the view will be at least as good as GONG on a good day and in my case sometimes better depending on local atmospherics. 

The other issue I have is, as the double stack unit is a big heavy lump and financially would be difficult to replace I am very carefull not to fumble it and therefore tend to let it sit on the scope just about all the time. That’s ope only sees the night sky for about a month a year which is a pity as the scope is superb on the night sky.

 

Good luck with whatever you choose and Best Regards

Carl

Attached Thumbnails

  • JPEG image.jpeg

  • BYoesle, Tyson M and Volvonium like this

#16 stubeeef

stubeeef

    Viking 1

  • *****
  • Posts: 822
  • Joined: 06 Aug 2012
  • Loc: NW NC

Posted 15 February 2020 - 04:36 AM

Saw a Lunt 80 double stack go quick in the classifieds for well under 4k



#17 George9

George9

    Surveyor 1

  • *****
  • Posts: 1,822
  • Joined: 11 Dec 2004

Posted 15 February 2020 - 11:24 AM

What do you guys like?

If you end up liking H-alpha a lot, you will likely end up changing telescopes over time, so don't try too hard to get it right on the first try.

 

A double-stacked 90mm Coronado in front of your NP101 (with 15mm blocking filter) would be a great choice if it makes the budget purchased used. For a lower budget, you could scale down to 60mm Coronado double stacked.

 

A Lunt LS80 DSII is also a great choice and what I use. It has some red glow unless you also add an internal filter, etc.

 

A single 90mm Coronado on your NP101 with a Quark on the back (no need for a blocking filter in that configuration because the Quark has its own) works but you won't get a full disk view due to the 4.2x Barlow in the Quark. But the advantage is that you could reuse your Quark on a bigger refactor in the future (single stack, and will need some ERF in front of the Quark). And you also could add the Coronado blocking filter (important) and you can use the 90mm single stack (without the Quark) and see the whole Sun on the NP101, just with less contrast. So more complicated, and more flexible, but I prefer the first two choices.

 

Or just get a Quark and a 2" UV/IR blocker to try it out on both your scopes and decide what to do next. The Oracle will almost provide a full disk view. But you will need to plug in the Quark, and it will be single stack (lower contrast).

 

You will eventually want a binoviewer, too.

 

George


  • BYoesle likes this

#18 BYoesle

BYoesle

    Fly Me to the Moon

  • *****
  • Posts: 6,790
  • Joined: 12 Jun 2004
  • Loc: Washington USA

Posted 15 February 2020 - 03:02 PM

 

 

I have a Televue Oracle III (76mm) and an NP101is (101mm) and my inclination is to just get the filters for one of these instead of buying a dedicated scope.

 

What do you guys like?

 

If you can afford them, the front etalon system is the best way to go. This is where instrument angles are non-existent and there is no magnification of field angles (see here) and therefore the filter performs at the best level it can for overall contrast and contrast uniformity. However, if you want more aperture than 90-100 mm, you will have to consider the internal etalon Lunts (100 & 152 mm objectives) or the eyepiece side filters from DayStar of Solar Spectrum used with suitable ERFs - I greatly prefer the Baader DERFs. The Quark is strictly an entry level filter, so don't expect miracles with it.



#19 gezak22

gezak22

    Gemini

  • *****
  • Posts: 3,300
  • Joined: 15 Aug 2004
  • Loc: On far side of moon. Send help.

Posted 15 February 2020 - 07:18 PM

I had assumed the quality of the telescope, at least the figure anyway, would affect the image in solar observing even with the narrow bandpass and thought the NP101 would be capable of a good image but if a dedicated scope works best then it's what I want.

Forget the quality of the telescope. When solar viewing, you will be entirely limited by daytime seeing, which is typically worse than night time seeing.

 

I too went through this exercise half a year ago. My conclusion was that 0.5 A buys me very little compared to 0.7 A, but it costs a whole lot. A binoviewer is a much more impactful accessory. In the end I got a single-stacked, pressure-tuned Lunt 80 from the classifieds. It's a wonderful passive (no battery needed, instant tuning) system that shows wonderful details on the rim when there is activity. Riding on a DSV-1, the 80 mm + binoviewer + a pair of 10 mm Delos is set up in 5 minutes. With the binoviewer installed, I can stay at the eyepieces for many minutes with no fatigue.

 

If you ever find yourself wanting to take a peek, and you are willing to drive to the wild west that is Goleta, shoot me an PM and I can give you a demo so you know what to expect from such a system.


  • briansalomon1 and Volvonium like this

#20 bigdob24

bigdob24

    Apollo

  • *****
  • Posts: 1,427
  • Joined: 19 Apr 2008
  • Loc: Central Illinois

Posted 15 February 2020 - 08:17 PM

Gezak 
Got to ask what Binos do you have that a pair of 10mm Delos are useable?

Thanks for the info

BD


Edited by bigdob24, 15 February 2020 - 08:17 PM.


#21 gezak22

gezak22

    Gemini

  • *****
  • Posts: 3,300
  • Joined: 15 Aug 2004
  • Loc: On far side of moon. Send help.

Posted 15 February 2020 - 08:24 PM

Gezak 
Got to ask what Binos do you have that a pair of 10mm Delos are useable?

Thanks for the info

BD

Binotron 27

 

It's a wonderful combination that works equally well on lunar and planetary.



#22 George9

George9

    Surveyor 1

  • *****
  • Posts: 1,822
  • Joined: 11 Dec 2004

Posted 15 February 2020 - 09:01 PM

Gezak 
Got to ask what Binos do you have that a pair of 10mm Delos are useable?

Thanks for the info

BD

Just curious if you were worried about usable in terms of the weight and width of the Delos, or usable in terms of the short FL? 11mm Delites work well with Denk II and Mark V. I think they would both hold the Delos, but I don't have a matched pair to actually test.

 

George



#23 bigdob24

bigdob24

    Apollo

  • *****
  • Posts: 1,427
  • Joined: 19 Apr 2008
  • Loc: Central Illinois

Posted 15 February 2020 - 09:24 PM

Weight doesn’t concern me , I’d be more concerned about width with my Denk II.

Ive got all the Delos line so buying one wouldn’t be too bad if they work.

I guess I could test the 10mm with another Delos that’s the same size just to see if they would physically work before I buy.

George do you use Delights in the Denks?

BD



#24 George9

George9

    Surveyor 1

  • *****
  • Posts: 1,822
  • Joined: 11 Dec 2004

Posted 16 February 2020 - 07:58 AM

Yes, the Delites are great in the Denks. No problem merging, good ergonomics (face fits in there fine). I basically use the 21mm Denks plus power switch for most work, and the 11mm Delites for high power. I could instead double-Barlow the 21s (OCS plus 2x Barlow) but the Delites were on sale at NEAF, and I find it easier to swap them in instead of adding yet another part in the LS80 DSII optical train: LS80 - circular polarizer - DSII - extension - FT focuser - Denk 2.3x OCS - B1800 - Powerswitch - Denk II - 11mm Delites. Putting a Barlow in front of the OCS then requires another extension to come to focus.

 

I was thinking the same thing about trying different Delos just to see how it feels, but I have 2" adapters on them and didn't feel like parfocalizing again.

 

George



#25 bigdob24

bigdob24

    Apollo

  • *****
  • Posts: 1,427
  • Joined: 19 Apr 2008
  • Loc: Central Illinois

Posted 16 February 2020 - 10:27 AM

George 

Just got my Denks out and stuck a 10mm and 8mm Delos “same physical size” in.

I have a mark on mine for the best merged view and there seems to be plenty of room for adjustment .

I held them like I was observing seemed to be plenty of “nose room” too.

I’ll be looking for an additional 10mm Delos in the future and try them out .

When I had my 20”FXQ dob I used 2” adapters on the 17 and 14 so I didn’t have to change the ParaCorr setting when changing eyepieces.

BD


  • George9 likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics