2 replies to this topic

[FEH]

Has anyone used a deep sky H-alpha filter with a solar filter? If so what were your results? I don’t need all the nope don’t do it’s or won’t work stuff. Looking for those who have actually combined the two, not arm chair quarterbacks. I know the band width differences…blah blah. That is not the question. Was there improved contrast? How much? Any attempts at using other types of secondary filters with a solar filter. What successes or failures did you have and with what kinds of secondary filters? Photos if you took any. Thanks.

Edited by FEH, 02 June 2023 - 07:01 AM.

[steveward53]

Welcome to the forum ...  

 

Try the "Search" facility first , to save everyone repeating answers you don't want to hear anyway ... 

Edited by steveward53, 02 June 2023 - 07:40 AM.

[MalVeauX]

Has anyone used a deep sky H-alpha filter with a solar filter? If so what were your results? I don’t need all the nope don’t do it’s or won’t work stuff. Looking for those who have actually combined the two, not arm chair quarterbacks. I know the band width differences…blah blah. That is not the question. Was there improved contrast? How much? Any attempts at using other types of secondary filters with a solar filter. What successes or failures did you have and with what kinds of secondary filters? Photos if you took any. Thanks.

Hi,

 

It works, as long as you understand that due to the wide bandpass that it's only photosphere features you will see. The angular resolution is lower as you increase wavelength (656nm in this case per your filter reference) which means lower contrast on features. However, longer wavelengths are less effected by atmospheric seeing (heavy blur from wavefront disruption, which lowers contrast) and so a long wavelength is good for poor seeing conditions to allow a chance to get focus. This is important because when seeing is poor, its difficult to even get focus and when you're slightly out of focus the blur increases dramatically. Combine all these elements (poor seeing, out of focus) and you get a heavily smeared low contrast low resolution image (which is common).

 

You will find almost everyone uses secondary narrowband filters with their primary white light filter system. Shorter wavelengths, such as 540nm, for improved angular resolution & contrast, but only when seeing is pretty good. Longer wavelengths such as 600~700nm range for when seeing is poor, being less effected by seeing conditions but at the cost of lower angular resolution.

 

Virtually every photosphere photo on this board is the example you're asking for.

 

Very best,