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Difference between the 2 DS for the LS100THA

Posted: Sun Feb 23, 2020 9:53 pm
by BigDob
What’s the difference besides price on the Internal DS and the 100mm DS.
I’ve 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

Re: Difference between the 2 DS for the LS100THA

Posted: Mon Feb 24, 2020 1:31 am
by DeepSolar64
BigDob,

I have a double-stacked Meade Coronado SolarMax II DS and like you only observe visually. I bought it first as a single stacked system and later added the second etalon to the front of the scope. I have learned pretty much where the tuning points are on the knob of the internal single stack and know pretty much where to tune it. I rarely take the second etalon off. I know pretty much where to start off with the first etalon and then set the second one. Different features take a bit different setting. Proms tune different from plages. It takes a bit of practice to learn to tune. At first all I could see was a big red ball. I was a bit disappointed at first. But like learning deep sky skills and planetary observing skills it takes time. I don't think the eye is very sensitive to the HA wavelength either.

On Proms, Single stack often DOES show them better. Double stacking dims the image a bit often making fainter ones invisible.

How big of a dob have you got and what brand? I have a 1983 model Coulter 10.1". It's old and I have had the mirror re-aluminized a few times. But it still works. I bought it new during my senior year in high school!

James

Re: Difference between the 2 DS for the LS100THA

Posted: Mon Feb 24, 2020 3:06 am
by BigDob
All I have now is a Lunt DS LS100THA. a Williams Optics 132mm .
Just sold my Starmaster FXQ20 and before that my favorite scope a 24” StarMaster with a Zambuto
Aperture always wins
BD

Re: Difference between the 2 DS for the LS100THA

Posted: Mon Feb 24, 2020 4:14 am
by DeepSolar64
WoW BigDob. You have went really big. I have toyed with replacing my old Coulter with a bigger instrument in the 16" class. Maybe eventually I will do it. I do have a close friend with a first rate 15" scope. Zambuto mirrors are awesome!

Lately I have been more into refractors. Many are more portable and my skies are certainly not as dark as the used to be. And for solar refractors dominate. I aspire to get a Lunt LS80THA eventually. A quark used on my Celestron NexStar 102 GT would be a cheaper option though.

James

Re: Difference between the 2 DS for the LS100THA

Posted: Mon Feb 24, 2020 1:15 pm
by BigDob
James
A Coulter 13.1 got me started A good scope , the most aperture for the buck.
I sold a Quark not too long ago and there are nice , just make sure you get a good one . I had to send my original back and the second was great.
BD

Re: Difference between the 2 DS for the LS100THA

Posted: Mon Feb 24, 2020 5:57 pm
by DeepSolar64
BD,
I had planned on a 13.1 myself or A 6" Criterion Dynascope. Both at the time were above what I could afford with my first job salary in high school so I got the 10.1". I ended up getting a second hand Criterion 6" a few years later. It has really good performance. I still have it and still use it.

James

Re: Difference between the 2 DS for the LS100THA

Posted: Sat Feb 29, 2020 12:12 am
by BigDob
Just an update
I’ve sent the Internal DS back and now have a LS100FHa ordered.
In about 3 months I’ll have a review of what I find.
BD

Re: Difference between the 2 DS for the LS100THA

Posted: Sat Feb 29, 2020 5:23 am
by DeepSolar64
BigDob,

Good luck on that LS100THA.

And I just ordered a Sky-Watcher 12" Dobsonian on Amazon for under 1000 bucks. It'll finally succeed my old Coulter 10.1" as my premier deep-sky scope after 37 years of use!

James