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ERF for 102mm refractor and DayStar Quark?

Filters Imaging Refractor Solar
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#1 ATL Gator

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Posted 12 April 2021 - 01:01 PM

Hi all -- 


After doing further research and receiving some very helpful advice in this forum, I've decided to get a DayStar Quark Chromosphere as my next foray into the world of H-alpha solar observing and imaging. While I seriously considered trading in my Lunt LS50 to buy a new LS80MT, the cost savings will allow me to keep my LS50 for casual observing and full-disk views. Meanwhile, I'll use the Quark for higher resolution imaging in H-alpha and eventually CaK and white light.


I plan to use the Quark with an Astro-Tech AT102ED refractor, which is a 102mm f/7 doublet with a 714mm focal length. In reviewing past threads regarding the Quark, I came across various opinions regarding (1) whether an ERF is needed at all with apertures under ~120mm and (2) if an ERF is needed, which one is best (e.g., DayStar, Baader D-ERF, etc.). I would rather be safe than sorry, so I will likely purchase an ERF even if one is not "needed," but I could use some help understanding the various options on the market. I am also wondering whether I need to couple the ERF with any other filters such as UV/IR.


Does anyone have any recommendations they can share?



#2 astro rocketeer

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Posted 12 April 2021 - 01:38 PM

Hi Scott, I actually have this same setup that you’re describing. I have the TS Optics 102mm F7 714mm fl ED Doublet and used with the Daystar Quark for imaging and binoviweing. I asked this same question when I first stared and the forum gave really good recommendations. I took Marty’s excellent advice and just got the Baader H-Alpha 35 nm CCD Filter (No. 2458380) and use that as in internal ERF (threaded to the 2” extension tube)followed by the DayStar Quark and then either the eyepiece or camera. The filter I used can be used up to 150mm aperture which I like about. I think anything >80mm aperture, you do need at least a UV/IR filter as an internal ERF (up to 120mm), then after that (120mm-150mm), recommend to maybe get a higher energy rejection filter like I’m using or the Baader Red CCD filter. I’ve done visual with these setup and you can see good proms, etc.. on a nice day of seeing conditions. I also printed 3D masks to mask it down to F10, F12, and F15 as well to make the quark more effective in giving more contrast.

Here are some pics of my setup train for imaging and visual.



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Edited by astro rocketeer, 12 April 2021 - 07:51 PM.

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