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

Double Stack question

  • Please log in to reply
3 replies to this topic

#1 bigdob24

bigdob24

    Viking 1

  • *****
  • topic starter
  • Posts: 733
  • Joined: 19 Apr 2008
  • Loc: Central Illinois

Posted 23 February 2020 - 02:25 PM

What’s the difference besides price on the Internal DS and the 100mm DS.

Ive got the Internal DS for my Lunt 100 and I’ve been able to use it about 4 times now and the jury is still out .

There was a little surface detail that was enhanced on 2 occasions and of coarse proms were visible. I tuned it by adjusting the primary for the best view and then install the DS and then tune it until the surface detail was enhanced and when it comes on band the whole disk brightens and you know your there.

Proms are nice but not as nice as SS.

What can be expected with the full 100mm DS in the view?

I know the red glow is gone , is there any difference on surface and prom detail , are they the same or enhanced over the Internal DS?

I would guess the 100mm DS is tilt tuned? I guess you would have to step to the side and adjust and go back and look or have someone adjust it while I watch as I don’t think I could reach it from the eyepiece?

Is it a set it and forget it .

I think if there are other advantages besides eliminating the red glow I’d be interested in learning about them.

I am just a visual observer too

BD

 

 



#2 TOMDEY

TOMDEY

    Fly Me to the Moon

  • *****
  • Posts: 5,939
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 23 February 2020 - 04:18 PM

Double-Stacked should be dramatically better on true H-alpha ~surface detail~ that would otherwise compete with plain vaniilla thermal red, also gets more Doppler discriminatory, so really need to finesse both filters in tandem, for best results. Proms do not benefit from DS, generally best with only one etalon. I've used both arrangements, one Pressure-Tuned and one Tilt-Tuned, and then two PTs. My preference is tilts that are up front... provided they are good/superior etalons. With two PTs, switching one in and out for surface/proms gets very old very fast. Most of us just leave both in unless obsessed with proms off the limb. [NOTE: One can, of course, see proms against the solar disc, just that the nomenclature/semantics generally implies they are seen against the black sky.]    Tom



#3 slavicek

slavicek

    Ranger 4

  • *****
  • Posts: 303
  • Joined: 01 Aug 2017
  • Loc: Massachusetts

Posted 23 February 2020 - 10:09 PM

I am not sure what's your question but I will tell you what I know. 

Few years back, when the Sun was still active, I bought 100mm pressure tuned Ha Lunt. Then, later on, I bought the second stack, also pressure tuned. The plan was to use single stack on some solar features and DS on other solar features.

Well, once you go double stack you never come back (to single stack). Everything is just much better, sharper and more visible. That I know and that should tell you a lot. Of course with double stack you can tune the telescope many different ways to see the Sun many different ways.

I do not believe there is a difference between internal or external tuning. I do believe that there's a difference between different etalon filters of the same brand.

That's all I know.



#4 bigdob24

bigdob24

    Viking 1

  • *****
  • topic starter
  • Posts: 733
  • Joined: 19 Apr 2008
  • Loc: Central Illinois

Posted 24 February 2020 - 08:31 AM

Thanks for the reply’s 

I’m going to ask my question a bit different in another thread.

BD




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