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Ha images taken in Ha with the Mewlon 250 on Sept 27

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#1 ch-viladrich

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Posted 11 December 2023 - 02:11 PM

Hi,

Here are two images taken on September 27 with the Mewlon 250, Baader 290 mm D-ERF and a double-stack Ha combination :

 

http://astrosurf.com...435-M250-Ha.jpg

 

http://astrosurf.com...445-M250-Ha.jpg

 

It is interesting to compare the features visible in the second Ha image with this ones visible in Ca K on the previous day. The scale is about the same :

 

http://astrosurf.com...CaK-014nmDS.jpg
 

The layer sampled in Ca K is lower than the layer sampled in Ha.

 

Clear skies,

 

Christian


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#2 Olimad

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Posted 11 December 2023 - 02:33 PM

Superbes images, Christian. Merci de les partager. 



#3 KMH

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Posted 11 December 2023 - 04:59 PM

Those are wonderful images, and a very interesting comparison.

 

Kevin



#4 ch-viladrich

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Posted 12 December 2023 - 05:55 AM

Thanks guys smile.gif



#5 Olimad

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Posted 12 December 2023 - 04:37 PM

To see the sun like this reminds me of some backgrounds on paintings made by Van Gogh.

 

Votre livre est-il toujours disponible à l'achat ? 



#6 hornjs

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Posted 12 December 2023 - 10:54 PM

Holy cow that is fantastic, thanks for sharing!



#7 rigel123

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Posted 13 December 2023 - 05:36 PM

Very reminiscent of Harald's images, beautiful!



#8 mmalik

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Posted 17 December 2023 - 08:54 PM

Here are two images taken on September 27 with the Mewlon 250, Baader 290 mm D-ERF and a double-stack Ha combination :

 

Beautiful pics; few questions...

 

 

I see you imaged with Mewlon 250; when you say double-stack Ha combination, would that be a double-stack on the same scope that has D-ERF installed? Not being familiar with D-ERF, I presume D-ERF would serve as a blocker and then you would have a double-stack on the same scope to make the complete package. Is that correct understanding on my part?

 

 

Please share a few pics of your Mewlon setup and how exactly you have D-ERF and double stack installed. Also what brand is your double stack? Is single or double stack required with D-ERF? What exactly is D-ERF and can it be used independently of a stack on solar? Sorry lot of questions.

 

 

I ask since I have an Epsilon 180 and am trying to understand how I can go about having a similar setup. Would such a setup be viable on E-180? What all exactly would I need to make it happen on E-180; brands/part numbers will be helpful. Hope you can answer all the question in greater detail and can contend with my novelty on such matters. Thanks in advance. Regards

 

 

 

post-205769-0-81043000-1625098757_thumb.


Edited by mmalik, 17 December 2023 - 09:01 PM.


#9 ch-viladrich

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Posted 18 December 2023 - 07:09 AM

Thanks to all !

 

 

Beautiful pics; few questions...

 

 

I see you imaged with Mewlon 250; when you say double-stack Ha combination, would that be a double-stack on the same scope that has D-ERF installed? Not being familiar with D-ERF, I presume D-ERF would serve as a blocker and then you would have a double-stack on the same scope to make the complete package. Is that correct understanding on my part?

 

 

Please share a few pics of your Mewlon setup and how exactly you have D-ERF and double stack installed. Also what brand is your double stack? Is single or double stack required with D-ERF? What exactly is D-ERF and can it be used independently of a stack on solar? Sorry lot of questions.

 

 

I ask since I have an Epsilon 180 and am trying to understand how I can go about having a similar setup. Would such a setup be viable on E-180? What all exactly would I need to make it happen on E-180; brands/part numbers will be helpful. Hope you can answer all the question in greater detail and can contend with my novelty on such matters. Thanks in advance. Regards

 

 

 

post-205769-0-81043000-1625098757_thumb.

I use a Baader Planetarium ERF.

 

Your Taka Epsilon is a telescope designed for deep-sky imaging, and certainly not for solar imaging.

 

You'd better use a small refractor (60-90 mm) or a dedicated solar telescope for solar astronomy. Better yet, if you have a small refractor, use Astrosolar sheet filter and start by white light solar imaging.

 

This is a bit of a learning curve there. Nothing difficult, but just leaning stuff one time at a time.

 

I suggest you have a look at "Best of Solar Forum". You will find a lot of information there.

 

Observing the Sun  by Jamey Jenkin is also a very good introduction to solar observing.

 

I hope you won't be frustrated by my answers. Again, there is nothing difficult there, but a leaning process.

 

PS :

- Here is a picture of the Mewlon 250 with the 290 mm ERF and the double-stack configuration :

 

http://www.astrosurf...on250-D-ERF.jpg

 

- Information on the filters used is given in the legend of the image.


Edited by ch-viladrich, 18 December 2023 - 07:11 AM.

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#10 mmalik

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Posted 21 December 2023 - 10:04 PM



I hope you won't be frustrated by my answers.

 

Thanks, much appreciated. I already have a solar scope (LS130MT/B3400FT-Straight/SingleStack); I am somewhat familiar with Lunt kind of implementation of a blocker along with etalon/s. My question are for Baader Planetarium ERF specifically and are as follows if you can help answer.

 

 

1. Can Baader Planetarium ERF be used by itself on an APO refractor with just a camera at the backend?

 

2. In other words, does Baader Planetarium ERF require a blocker [I don't mean an etalon here] at the backend in an APO refractor scenario?

 

3. Or does Baader Planetarium ERF require a blocker along with an etalon at the backend in an APO refractor scenario?

 

4. Simply put, what does Baader Planetarium ERF require to function properly if it can't be used (alone) by itself.

 

5. Is Baader Planetarium ERF intended more for photography or visual?

 

 

As you can tell, my questions are specific to Baader Planetarium ERF.  Thanks in advance. Regards

 

 

.



#11 hopskipson

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Posted 21 December 2023 - 10:21 PM



 

Thanks, much appreciated. I already have a solar scope (LS130MT/B3400FT-Straight/SingleStack); I am somewhat familiar with Lunt kind of implementation of a blocker along with etalon/s. My question are for Baader Planetarium ERF specifically and are as follows if you can help answer.

 

 

1. Can Baader Planetarium ERF be used by itself on an APO refractor with just a camera at the backend?

 

2. In other words, does Baader Planetarium ERF require a blocker [I don't mean an etalon here] at the backend in an APO refractor scenario?

 

3. Or does Baader Planetarium ERF require a blocker along with an etalon at the backend in an APO refractor scenario?

 

4. Simply put, what does Baader Planetarium ERF require to function properly if it can't be used (alone) by itself.

 

5. Is Baader Planetarium ERF intended more for photography or visual?

 

 

As you can tell, my questions are specific to Baader Planetarium ERF.  Thanks in advance. Regards

 

 

.


The Baader ERF is just an energy rejection filter and cannot be used alone.  It is used in conjunction with a rear-mounted mica spaced Hydrogen alpha etalon.  Other ERFs can be used with narrow-band Calcium K and H band filters from Lunt and Daystar and Tri-band ERFs can be used with narrow G band filters.

 

Do not attempt to use an ERF alone!


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#12 mmalik

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Posted 22 December 2023 - 04:42 PM

Do not attempt to use an ERF alone!

 

Folks, I am asking direct questions and would appreciate simple and direct answers. So please let me rephrase my question and if you can answer in exact same terms as depicted in the diagram. Thanks in advance. Regards

 

 

Question: Can D-ERF at the front of say on a 130mm APO can be paired with say Lunt B1200mm diagonal at the back-end without any intervening etalon/s? In other words, can Baader RG46 H-a Filter (as depicted by Baader) can be directly replaced with say Lunt B1200? Note: I presume Baader didn't depict any intervening etalon/s in this picture; is that correct assumption on my part? Would this be a viable and safe solution?

 

 

.

Attached Thumbnails

  • D-ERF3.jpg


#13 hopskipson

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Posted 22 December 2023 - 09:15 PM

The Solar Spectrum is the mica spaced etalon.

Others with more experience and knowledge than me will chime in as to the safety/danger of using just a blocking filter instead of the etalon. I don’t see the point of it since it would show only the photosphere. You would be better off just using a Hershel wedge or Baader Solar film.

#14 mmalik

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Posted 23 December 2023 - 12:56 AM

The Solar Spectrum is the mica spaced etalon.

Others with more experience and knowledge than me will chime in as to the safety/danger of using just a blocking filter instead of the etalon. I don’t see the point of it since it would show only the photosphere. You would be better off just using a Hershel wedge or Baader Solar film.

 

I understand, but here is my dilemma...

 

 

If one is supposed to use an etalon followed by a blocker at the backend, then what (the heck) is Baader ERF is doing at the front end? An etalon followed by a blocker is a typical Lunt solar system design. What's the function of Baader ERF then if one is still supposed to use an etalon and a blocker with it? Hope you get my point. Regards

 

 

.


Edited by mmalik, 23 December 2023 - 02:48 PM.


#15 ch-viladrich

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Posted 23 December 2023 - 05:38 AM

Hi,

 

Here are some elements of answer :

 

Hi,

 

An ERF is an Energy Rejection Filter. Its purpose is to reject a large part of the energy that would otherwise enter the telescope.

 

The total energy transmitted by the Baader ERF is about 17%. Transmission is about 80 nm bandpass centered on Ha, an IR from about 1600 nm.

 

1) "Can D-ERF at the front of say on a 130mm APO can be paired with say Lunt B1200mm diagonal at the back-end without any intervening etalon/s ?"

 

=> Yes, but you would only see the photosphere since the bandpass of the Lunt BF is in the range of 5 to 10 A, and < 1 A is needed to see the chromosphere.

To get down below 1 A, an etalon is needed. The transmission profile of an etalon presents a number of peaks of transmission (= interference orders). The role of a BF is to isolate the peak of transmission centered on Ha. See :

http://astrosurf.com...-spaced-07A.jpg

 

So an etalon is always used with a blocking filter. The RG46 Solar Spectrum filter includes :

- a mica-spaced etalon,

- a 10 A blocking filter,

- and various additional filters (polarizers, ITF, RG630).

 

This is why we can see the chromosphere when using the RG42, and not when using only a BF.

2) "In other words, can Baader RG46 H-a Filter (as depicted by Baader) can be directly replaced with say Lunt B1200 ?"

=> certainly not, since the Lunt contains no etalon.

3) "I presume Baader didn't depict any intervening etalon/s in this picture; is that correct assumption on my part?"

=> Can you give the context and link to this figure. Information is missing there to understand the message conveys by the figure.

4) "Would this be a viable and safe solution?"

=> If "viable" means chromosphere can be seen with this combination, then the answer is no.

5) " Note: I presume Baader didn't depict any intervening etalon/s in this picture"

=> There is an etalon in the RG46

6) "If one is supposed to use an etalon followed by a blocker at the backend, then what (the hell) is Baader ERF is doing at the front end?"

=> otherwise the etalon + blocker received too much energy and degrade more or less rapidly. So, an ERF is needed at the entrance of the teelscope to reduce the amount of energy falling on the etalon (and blocker).

7) "An etalon followed by a blocker is a typical Lunt solar system design."

Lunt solar telescopes also include an ERF.

 

Hope this helps,

 

Christian


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#16 mmalik

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Posted 23 December 2023 - 08:55 AM

...Mewlon 250, Baader 290 mm D-ERF and a double-stack Ha combination :

 

Thanks for the detailed write-up; does that mean double-stack in your configuration is an RG46? Does a D-ERF at the front and RG46 at the back complete your Mewlon configuration? Or are there other intervening components in your setup? Regards

 

 

.


Edited by mmalik, 23 December 2023 - 08:55 AM.


#17 ch-viladrich

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Posted 23 December 2023 - 09:15 AM

Thanks for the detailed write-up; does that mean double-stack in your configuration is an RG46? Does a D-ERF at the front and RG46 at the back complete your Mewlon configuration? Or are there other intervening components in your setup? Regards

 

 

.

The double-stack configuration I use is indicated in the legend on the images : Coronado SMn-35 0.5 A + DayStar PE 0.6 A.

 

Here is again an image with all this equipement :

http://www.astrosurf...on250-D-ERF.jpg

 

We have Baader 290 mm D-ERF >> Mewlon 250 >> AiryLab 2.7x telecentric >> Coronado SMn-35 0.5 A Ha filter >> DayStar PE 0.6 A Ha filter


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#18 mmalik

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Posted 23 December 2023 - 03:03 PM

Lunt solar telescopes also include an ERF.

 

While I've some idea what you mean by ERF, I don't see such a component or term being used by Lunt. Where exactly do you think is an ERF (specifically) is in a Lunt solar system. This... is how Lunt defines an H-alpha solar scope. Regards

 

 

Note: I presume 'Lunt H-alpha Module' in the chart represents an etalon although Lunt doesn't use such a term in the chart.

 

 

Link...

Attached Thumbnails

  • Lunt_H-alpha7.jpg

Edited by mmalik, 23 December 2023 - 03:16 PM.


#19 ch-viladrich

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Posted 24 December 2023 - 07:16 AM

While I've some idea what you mean by ERF, I don't see such a component or term being used by Lunt. Where exactly do you think is an ERF (specifically) is in a Lunt solar system. This... is how Lunt defines an H-alpha solar scope. Regards

 

 

Note: I presume 'Lunt H-alpha Module' in the chart represents an etalon although Lunt doesn't use such a term in the chart.

 

 

Link...

If you read the table you've copy/paste in your message, you can read "Blocking filter" and not "etalon."

 

I suggest the following readings :

- message #15

 

- solar forum usefull threads (see part 3) :

https://www.cloudyni...eads-and-links/

 

- Lunt technical articles :

https://luntsolarsys...nical-articles/

 

This one explains what an etalon is :

https://luntsolarsys...escopes-can-do/

 

This one explains what is inside a Lunt 50 solar telescope (including an ERF) :

 

https://luntsolarsys...specifications/

 

There is nothing complicated there. Only a leaning curve to be taken step by step.


Edited by ch-viladrich, 24 December 2023 - 07:20 AM.



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