Last but not least, my biggest Mod

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
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Solar-Cologne
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Last but not least, my biggest Mod

Post by Solar-Cologne » Wed Nov 18, 2015 3:15 pm

Hello sun friends,

The components for my last H-Alpha-Mod.

an older Meade ED178 f9 refractor, 2nd generation with the stable lens mount, a rare and very good scope, in DS too.
W.Lille 160mm front C-ERF
W.Lile 50/50 h-alpha-system,
with one of the best 3x military telecentric, minimum 20 meters !!!

50mm original and very rare SolarScope etalon
tiltable 50mm Blockingfilter, with 52mm tiltable BG38
So the setup works with f=30

Five h-alpha enthusiasts use this system.
http://sonnenfernrohr.de/produkte-fuer- ... a-systeme/

There is so much light in this system, i often need a second 50mm BG38 , B&W-optics pro.
This project finished in august this year, and at first i make some pictures with this setup....seen here in the forum.

Visual I had bad luck this year here in cologne/germany.
Now i must wait since march/april to pick the sun from my location...... :cry:
you can not have everything. :D

The second picture show you a part of "Solar-Cologne"

sunny Greetings :D
Achim
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marktownley
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Re: Last but not least, my biggest Mod

Post by marktownley » Wed Nov 18, 2015 5:03 pm

Looks good! May I ask a couple of questions please?

Is the blocking filter and BG38 before or after the etalon?

If it is after the etalon do you have any thermal stability issues with etalon tuning as I notice you are using a C-ERF?

Thanks

Mark
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Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

Solar-Cologne
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Re: Last but not least, my biggest Mod

Post by Solar-Cologne » Thu Nov 19, 2015 2:46 am

Hi Mark,

the BG38 and the Blockingfilter are behind the etalon.
I can not answer your question, because i must wait till march/april to have a look at our sun, sorry. :cry:

In the winter i dont watch h-alpha, only with my PSt or Lunt 60, because i dont know, whats happend with the filters at cold temperatures.

sunny Greetings :D
Achim

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Valery
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Re: Last but not least, my biggest Mod

Post by Valery » Fri Nov 20, 2015 7:50 am

Solar-Cologne wrote:Hi Mark,

the BG38 and the Blockingfilter are behind the etalon.
I can not answer your question, because i must wait till march/april to have a look at our sun, sorry. :cry:

In the winter i dont watch h-alpha, only with my PSt or Lunt 60, because i dont know, whats happend with the filters at cold temperatures.

sunny Greetings :D
Achim
If your H-a etalons are air-spaced, nothing will happens with them. Only solid spaced etalons with immersion oil inside are not suitable
for using them at freeze temp.

Another points:

1. You writes that that unique military tele centric gives 20(!) meters of focal length.
Then you writes that the system works at F/30 with entrance diameter of 160mm. This corresponds to less than 5m focal length.

2. Too much light? I doubt it. NEVER enough! May be for visual, then variable polarizer can be used for brightness adjustment.
If too much light this typically indicate that your filter bandpass is too wide. A really narrow etalons typically have less light than
we want them to have.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

Solar-Cologne
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Re: Last but not least, my biggest Mod

Post by Solar-Cologne » Fri Nov 20, 2015 10:25 am

Hello Valery,

I like it, that you and some others are so interested in h-alpha.

The filter mounts are smaller in cold weather, it could burst a too tightly seated filter.

sorry, ...google translate for me.. :D :D

The ED178 has 1600mm, and with the 3x telecentric the scope has 4800mm, right.

Wolfgang Lille said to me, that this special telezentric has a parallel beam path from about 20 meters.

i hope, i find the right words. :mrgreen:

sunny Greetings :D
Achim

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Valery
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Re: Last but not least, my biggest Mod

Post by Valery » Fri Nov 20, 2015 1:41 pm

Solar-Cologne wrote:Hello Valery,

I like it, that you and some others are so interested in h-alpha.

The filter mounts are smaller in cold weather, it could burst a too tightly seated filter.


Achim
Again, this is just your personal guess. I have tested several air-spaced etalons even at -15C with no problems.

My information is my own _real_ experience.

And if you will search for my posts last winter you can see what kind of images one can take with air-spaced
etalons under freezing temperatures.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

Solar-Cologne
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Re: Last but not least, my biggest Mod

Post by Solar-Cologne » Sat Nov 21, 2015 3:26 am

the next step is doublestack.
A PST etalon behind the 50mm Lille Blockingfilter.

sunny Greetings :D
Achim

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