Girish avatar

I have a question, couple of days back I was taking Solar photograph and I followed the same steps , same equipments, same duration of the frame etcs that I did in my earlier shot where I have to see lot of activities around the Sun as well as on Surface but 2 days back when I took the solar photograph, it was not the same. Does Sun have different view when those dark spots shows up in winter (just a theory) vs fall vs Summer? I know you might think what kind of silly question it is and I am trying to understand the missing piece in this.

This one I took 2 days back!

šŸ“·Sun_1 copy.jpg

and this one was in the fall season

šŸ“· Canada goose migration over the Solar exposureCanada goose migration over the Solar exposure

andrea tasselli avatar
The one at the top looks like a "white" light picture (only colorized yellow) while the one at the bottom looks like an H-alpha band picture so no surprise they look quite different. Since you don't state what was the equipment used I can hardly give more insight about what is going on. If an etalon was involved then the stiff cold being experienced in some part of the world would lead to a de-tuning and you'd get you just a continuum light type of image. Finally, yes, the Sun aspect varies quite a bit day to day or even hours by hours.
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Samuel Müller avatar

Since you’re using a Lunt LS50THa (I have a Lunt LS60THa), I believe it’s possible that the IR filter has degraded. It’s the red filter in the filter block, near the ocular holder. Aim on the sun, and look through it without an ocular. See if it’s a clear transparent red, or if it has bubbles or stains. On the second case, it has degraded and you need to change it. I contacted Lunt directly and they sold me a new one. Another possibility is the UV filter (the blue filter) on the other site of the filter block. See if it’s transparent. If not, you can polish it or change it (recommended).

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Girish avatar

andrea tasselli Ā· Feb 5, 2026, 11:42 AM

The one at the top looks like a "white" light picture (only colorized yellow) while the one at the bottom looks like an H-alpha band picture so no surprise they look quite different. Since you don't state what was the equipment used I can hardly give more insight about what is going on. If an etalon was involved then the stiff cold being experienced in some part of the world would lead to a de-tuning and you'd get you just a continuum light type of image. Finally, yes, the Sun aspect varies quite a bit day to day or even hours by hours.

Thank you, Andrea! I am using LS50THa, AM3, ASI533MM Pro in both the cases and have exposure capture.

Girish avatar

Samuel Müller · Feb 5, 2026, 01:47 PM

Since you’re using a Lunt LS50THa (I have a Lunt LS60THa), I believe it’s possible that the IR filter has degraded. It’s the red filter in the filter block, near the ocular holder. Aim on the sun, and look through it without an ocular. See if it’s a clear transparent red, or if it has bubbles or stains. On the second case, it has degraded and you need to change it. I contacted Lunt directly and they sold me a new one. Another possibility is the UV filter (the blue filter) on the other site of the filter block. See if it’s transparent. If not, you can polish it or change it (recommended).

Thank you, Samuel! I got this telescope 2 months back and I dont believe it would degrade this quick šŸ™‚ā€ā†•ļø but who knows we live in technology world where every day things are changing šŸ˜€

Samuel Müller avatar

Believe me… it can degrade even quicker 🤣

šŸ“· 1.jpg1.jpgšŸ“· 2.jpg2.jpgšŸ“· 3.jpg3.jpgšŸ“· 4.jpg4.jpgšŸ“· 5.jpg5.jpgI took these images between october/22 and march/23. See how fast it degraded.

Samuel Müller avatar

And that’s after I changed the red filteršŸ“· 6.jpg6.jpg

Girish avatar

Samuel Müller · Feb 5, 2026, 02:10 PM

And that’s after I changed the red filteršŸ“· 6.jpg6.jpg

This help! question would now be, is that a free replacement knowing that I got new piece 2 months back? and if so then do you know the process? 😊

Samuel Müller avatar

This I can’t answear to you. You shoul talk directly to your vendor or to Lunt.

Rainer Ehlert avatar

Girish Ā· Feb 5, 2026,

I now understood your problem. The upper one look like white oight while the second one is correct.

Girish avatar

Samuel Müller · Feb 5, 2026, 04:57 PM

This I can’t answear to you. You shoul talk directly to your vendor or to Lunt.

Thank you! I reached out to Lunt and waiting to hear back, I will share the findings for others in case if they face same!

LLichter avatar

Could you tell me the steps you did when you took the images 2 Days ago?

The LS50Tha uses a pressure tuner too get the etalon filter on band by changing the pressure around the etalon.

Sometime after a long time in storage or when changing altitude the pressure in the etalon housing has to be reset to the current outside pressure in order to tune the etalon filter.

Could you try ā€œburpingā€ the etalon by unscrewing the black cylinder on the side until its all the way out. You might here the air rush in/out as the pressure equalizes.

https://solarchatforum.com/viewtopic.php?t=44114

Than try tuning the filter by turning until the contrast is most even.

If this does not work there might realy be a problem with the filter as Samuel Müller said.

I hope this helps.

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Girish avatar

LLichter Ā· Feb 6, 2026, 04:34 PM

Could you tell me the steps you did when you took the images 2 Days ago?

The LS50Tha uses a pressure tuner too get the etalon filter on band by changing the pressure around the etalon.

Sometime after a long time in storage or when changing altitude the pressure in the etalon housing has to be reset to the current outside pressure in order to tune the etalon filter.

Could you try ā€œburpingā€ the etalon by unscrewing the black cylinder on the side until its all the way out. You might here the air rush in/out as the pressure equalizes.

https://solarchatforum.com/viewtopic.php?t=44114

Than try tuning the filter by turning until the contrast is most even.

If this does not work there might realy be a problem with the filter as Samuel Müller said.

I hope this helps.

Than you!! I did follow the same steps that I did back in Early Jan but again I will try when the sky get’s clear and start.

Girish avatar

Thank you Everyone! Finally I was able to redo and this time it worked!! I believe when I was doing it other day I must have done something wrong! Anyway all feedback helped me to try and redo but slowly this time šŸ˜€šŸ˜€šŸ˜€

šŸ“· Sun_5.jpg