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H-Alpha Double-Refractor 120 / 135 / 150mm Aperture ?

Posted: Thu Nov 12, 2015 6:35 am
by Solar-Cologne

I am a new ;Member here and my Name is Achim, from Cologne/Germany.
Sorry, but my english is not so good, i hope, i learn a little bit here in SolarChat :D

I am an Hobby-Astronomer since 6 Years started with an old TASCO Newtonian 114/900.... :mrgreen:
By the Time, i learn it to love our Sun.

I found the way in this Chat, because i want to have worldwide Connections with H-Alpha-Telescope Users.
Why ?
I am inquisitive in H-Alpha especially selfmade Telescopes.
At assemblies Scopes, i use two Coronado-PST, and a third PST-Etalon in an Aluminium case, mecanical Tuning, T-2 Adaption with an Baader TZ-4 Telezentrik.
By the Time i made a selfmade Scope with PST-Conversation and one with Lunt60-Conversation.
My last Step is an old Meade ED-178 with f=30, Doublestack. Its in work.

My Dream is an H-Alpha Double-Refractor with two C-ERF and min. 120mm Diameter or greater, without Frontetalons, at the end the Matsumoto Two-Mirror-System.

Is there anybody, using a Binocularscope like this ?
Or has somebody the same dream...?

My best H-Alpha Friends are Oliver Smie / and Wolfgang Lille /
I am lucky to know them both.

sunny Greetings :D

Re: H-Alpha Double-Refractor ?

Posted: Thu Nov 12, 2015 8:54 am
by Derek Klepp
There will be someone here with knowledge Achim.I am still learning just basic modding.
Don't forget to post some pictures of your scopes.

Re: H-Alpha Double-Refractor ?

Posted: Thu Nov 12, 2015 10:39 am
by Solar-Cologne
Hello Derek,

oh my, i have a lot of Sun-Scopes.... :mrgreen:

I dont wont to make a mistake here in Solarchat.
In which Board i can post my Pictures ?

sunny Greetings :D

Re: H-Alpha Double-Refractor ?

Posted: Thu Nov 12, 2015 7:21 pm
by marktownley
Hi Achim, welcome to the forum! You certainly have a lot of scope setups there. Never tried the binocular scopes like you talk about, but certainly sounds interesting. You can post your pictures in any of the boards here. :)

Re: H-Alpha Double-Refractor ?

Posted: Fri Nov 13, 2015 7:16 pm
by Solar-Cologne
Hi Mark,

My Plan is to build a H-Alpha Binoscope with my self made 6" f8 FH-Binoscope with Matsumoto Mirror-System, with the build in Pentax 6x7 Helicoid-Focussers to adjust the Eye-Diameter.

I build it, because i like the big Fujinon 150 Binoculars.
My Scope is better than the Fujinon, because i can up to 300x .... :D
The Fujinon has a shorter focalratio and the wider Field....ok.

This Refractors are the older Bresser types from the Year 2000, not adjustable Lenses.
I have two Al Jaegers 6" f8 brand new Lenses.
now, i will make the Adapters for the Jaegers, they are 10 Times better than the Bresser, like an Semi-Apo....wouw.

I have two W.Lille C-ERF, one 135mm and the other 160mm and two PSTs,

I need only five Adapters and a second Zeiss-Abbe-Barlow to make a self-made 120mm H-Alpha-Binoscope.

sunny Greetings :D

Re: H-Alpha Double-Refractor ?

Posted: Sat Nov 14, 2015 8:41 am
by marktownley
Wow, that is a cool setup!

Re: H-Alpha Double-Refractor ?

Posted: Sun Nov 15, 2015 2:48 am
by MapleRidge
Welcome Achim...

That bino scope is rather will be interesting to follow this project as it develops.


Re: H-Alpha Double-Refractor ?

Posted: Mon Nov 16, 2015 1:44 pm
by Valery
I am envious with the green background and ground everywhere there. This is the nicest environment for a good solar seeing which is the key in this hobby.


Re: H-Alpha Double-Refractor ?

Posted: Mon Nov 16, 2015 5:58 pm
by Bob Yoesle
Hi Achim,

Impressive, but I'm not sure it would be the best approach.

1. OTA alignment seems like it might be a problem in order to get coincident visual fields.

2. For the twin scope you will need two etalons. Internal collimated etalons with the PST collimator-etalon-refocus lenses would be very complex with the Matsumoto mirror system and Pentax focusers. Using telecentric based filters (DayStar, Solar Spectrum) will give you a huge EFL, making OTA and internal optical alignment issues even more critical.

3. There are no commercially available front etalons over 100 mm in diameter. They are expensive, and you would need two. It would be better to use them double stacked on a single OTA with a binoviewer.

I certainly don't want to discourage you from trying, but in the end, you would probably be better off using a single 120 mm objective with a LS 60 or (better) LS 80 internal etalon system, with the appropriate DSII for double stacking if desired, and using a binoviewer.

Just my 2 cents worth...

Re: H-Alpha Double-Refractor ?

Posted: Tue Nov 17, 2015 11:18 pm
by Solar-Cologne
Hello sun-friends,

Thanks for interesting this project.


My thoughts to built this scope, I discussed with Oliver Smie.
Our first plan was to use the brand new Daystar-Quarks.....fine, a good idea.
We think, its a very good h-alpha-component, and its the right time when started in the market.

We speak with M.Ludes APM/Telescopes, if the next batch arrive here in Germany we want to test them all and i get two of the best one...... :D
But whats happend.....they all are, to put it mildly, not so good..... we were disappointed :cry:

What we can do ?
Then it occurred to me, to use my two Coronado-PSTs.
All components are available, its cost me no money, only the five adapters..... :D

At next time i will test it, with two friends, with a single refractor, to put the etalon between the tube and the Matsumotos and the blockingfilter with barlow and eyepiece on the top

Oliver said, it will work.....maybe later, we will see... :idea:
About the biggest Frontetalons:
Today, i ask Wolfgang Lille, he knows all about H-Alpha components.
Coronado has only built 5 pieces of a 140mm fronetalon in about the Year 2000 or earlier. It costs about 32.000,- DM, old German D-Mark, 16.000,- €.
But when they build it today, i think it costs 32.000,-€.
One User in Germany has two of them....not me.... :D

sunny Greetings :D

Re: H-Alpha Double-Refractor ?

Posted: Mon Mar 23, 2020 6:17 am
by Solar-Cologne
Hello Sunny Girls and Boys,

After a long period of Astro-abstinence........becaus i have more Hobbys......Highend HiFi.......and Motorcycles.......and my best Astrofriend Sascha, he was an H-Alpha Enthusiast too and my Parents died. :cry: :cry: :cry:

Now i will new started the 120mm H-Alpha Doublerefraktor Projekt, because I'm a purely visual H-Alpha observer.

I got the latest ones of Matsumoto EMS U-L with silver coated Mirrors....97,5 % Reflction and 148mm Lightpath.

The average reflectivity through the visible spectrum per one mirror is as high as 98.5 percent, and 97 percent of the incoming light is secured even after 2 times of reflections.

I have two very good original C-ERFs 135mm and 160mm

Two Skywatcher 6" f8 Refraktors, very good for H-Alpha.

Two Coronado PSTs

Two Matsumoto EMS U-L

Now, i need some Adapters to built this Binoscope......later.

Yesterday i watched the sun for the first time in this Year 2020 with my single 120mm 6" f10 PST.

sunny Greetings :D
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Re: H-Alpha Double-Refractor ?

Posted: Mon Mar 23, 2020 8:23 am
by marktownley
Looks good Achim. What happended to the 2 scopes from earlier in the post?

Re: H-Alpha Double-Refractor ?

Posted: Tue Mar 24, 2020 6:12 am
by Solar-Cologne
Good morning Mark,

The 2 telescopes are still available.......I said it in the last post


Re: H-Alpha Double-Refractor ?

Posted: Thu Mar 26, 2020 7:16 am
by robert
Let us know how you get on! 🙄

Re: H-Alpha Double-Refractor ?

Posted: Thu Mar 26, 2020 10:28 pm
by Solar-Cologne
I have now also received a second Zeiss-Abbe Barlow at a ridiculously low price.

Sometimes i will use a 0,5 x Reducer 1-1/4".

W. Lille now produces the necessary adapters for me.


sunny Greetings from Cologne

Re: H-Alpha Double-Refractor ?

Posted: Fri Mar 27, 2020 5:10 am
by Solar-Cologne
I will send you a PM

Re: H-Alpha Double-Refractor ?

Posted: Sat Mar 28, 2020 6:52 am
by Solar-Cologne
I stupid ...... enlightenment came to me this morning. 💡

I have a one-off production of a PST etalon, built into a red anodized aluminum housing, which can be tilted from the outside

T-2 adaptation and mounted afocal original PST lens system, removable to use a real telecentric.

So screwed the afocal lens system back in and looked into my adapter box ......

Hooray, everything is there.

I first fix the PST block filter unit without PST-ERF with silicone or similar material to test.

Now I'm curious to see if I come into focus .......

sunny Greetings

PST-Kippetlon an EMS-01.jpg
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Re: H-Alpha Double-Refractor ?

Posted: Sat Mar 28, 2020 4:54 pm
by Solar-Cologne
Today I was able to test.

A friend helped me with that.

One of the two Skywatcher 6 "f8 refractors with 135 C-ERF and the adapted PST tiltable etalon saddled on the EQ-8.

Then sighted the sun.

My friend operated the focuser and the tiltable PST etalon.

I held the block filter unit (without PST ERF) on the 1-1 / 4 "nozzle with both hands.

I learned that Sahara dust is in the atmosphere, so I didn't see Venus in the daytime sky.

No H-Alpha in the sun, very dark sun through the dust .... but we both saw the Etalon-Donat, which tipped over the surface of the sun ..... so this the focus

..... i am Very Happy.

I will use the tiltable etalon on one refractor and the original etalon on the second.

Now I can take the measurements and take care of the adapters.

In the second photo you can see the focus when the block filter is attached.

sunny Greetings
PST-Kippetlon an EMS-02.jpg
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Re: H-Alpha Double-Refractor ?

Posted: Sun Mar 29, 2020 11:22 pm
by Solar-Cologne
I had a next Idea..... :idea:

I have already found an inexpensive adapter solution. :D

The lower PST socket under the BF 5 has an M33 x 0.75 thread.
The 1-1 / 4 "eyepiece holder has 31.8mm.
I will have it turned 5mm deep to 33mm and glue the lower PST socket there.

Now I need only 3 adapters .... but I currently have no more money .... broke.

First of all to mount the PST etalon on a 2 "focuser, as AOK-Swiss also offers. It is too expensive for me.

An adapter with an M50x1 internal thread and 2 "internal dimension to insert the etalon into the Matsumotos.

At least a adapter with rear T-2 external thread and front 2 "external dimension to mount the PST tiltable etalon on a 2" focuser.

Then I can finally pamper my eyes. :D :D :D

Re: H-Alpha Double-Refractor ?

Posted: Mon Mar 30, 2020 9:47 am
by Solar-Cologne
Well, progress is slow ... unfortunately, too slow. :cry:

My workshop for turning work, where Mathias Wirth / APM M.Ludes has his parts made, is fully booked.
I persuaded him tomorrow to at least quickly expand the two 2 "/ 1-1 / 4" reducers for the lower PST block filter nozzle to 33mm.
And it will be cost 10,-€
So I can glue the two sockets there.
I can be very persistent when I have a goal in mind. :D :D :D

I try to keep the total costs under 4000, - €.

With two Baader 1.25x glass path correctors I can use 135mm aperture !

Sunny Greetings

Re: H-Alpha Double-Refractor ?

Posted: Tue Mar 31, 2020 4:37 pm
by Solar-Cologne
Yeah ... it's going ahead, faster than expected.

Peter Deuster, metal processing, Cologne, Widdersdorfer Str. 215

now makes me all 3 missing adapters by Friday noon, including PST etalon internal thread M 50x1 ...... insane, this adapter is nowhere to be bought.

Furthermore I have to widen my mauell fork assembly, at that time with Stefam Schimpf / Astromechanik in Volkach, for the 2 x 6 " Bino.

Originally there was a 2 x 120mm bino in there.

So I need the 2 horizontal aluminum plates new.

I went to Cologne, to "Wilms Metallhandel" .... Fa. sits next to Peter Deuster, and had the aluminum plates cut to me.

Then I saw 0.3mm red anodized aluminum material in a special offer in the sales room ... and had it cut to size for the two panels ...

Now glue on the red anodized sheets then drill the holes and the fork is ready.

See you on Friday.....

sunny greetings
Peter Deuster.jpg
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Wilms Metallbau Köln.jpg
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Alu von Wilms.jpg
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Meine Gabelmontierung.jpg
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The last photo shows the construction of the fork mount.
The picture is an advertising photo by Stefan Schimpf / Astromechanik in Volkach / Germany.

Re: H-Alpha Double-Refractor ?

Posted: Tue Mar 31, 2020 6:52 pm
by marktownley

Re: H-Alpha Double-Refractor 120 / 135 / 150mm Aperture ?

Posted: Wed Apr 01, 2020 6:34 pm
by DeepSolar64
awesome looking refractors!!!

Re: H-Alpha Double-Refractor 120 / 135 / 150mm Aperture ?

Posted: Thu Apr 02, 2020 9:05 pm
by Solar-Cologne
Today i tested one Refraktor for my Binoscope 120mm Aperture 6"f8 (H-Alpha f=10 ) with 135er C-ERF, PST-Etalon, Matsumoto EMS U-L, erecting Mirror System, PST BF 5mm a little bit tilted without the original ITF-Filter, Zeiss-Abbe Barlow with ClickLock 2,25 x and a Microskopocular WF 20x ( 12,5mm ).

It was a little cloudy in front of the sun, but still 216 x magnification ... wouw.

in the Bino 302 x !!! :D

You have to consider that when you look at real bino, our brain produces a 1.4 x larger image than monocular.

With Two Scopes....?.....400 x......500 x....we will see.

Do the test yourself with binoculars.
Alternately cover one of the lenses ....

Re: H-Alpha Double-Refractor 120 / 135 / 150mm Aperture ?

Posted: Sun Apr 05, 2020 9:16 am
by Solar-Cologne
I am currently widening the hand-guided fork mount by Stefan Schimpf / Astromechanik.

It was previously designed for a 2 x 120 FH bino.

My 2nd PST cannot be disassembled at the moment .......
The adhesive, similar to Locktite, sticks enormously.

sunny greetings
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