Increasing contrast in solar Ha observations

[aramitsharma]

What do you use to increase contrast in the visual observations through your solar scope. I have Coronado single stack 60mm. The double stack unit are under production apparently but have already missed the expected ready by dates. 

Till they get it out in the market obviously at exorbitant rates, are there any filters I can buy to boost the contrast?

 

[Paz]

I use a polarising filter with a daystar quark and that can tune the brightness to get a better view depending on exactly what feature I'm looking at, but it relies on the quark itself polarising the light first. I don't know if the Coronado you have polarises the light or not.

[Peter Drew]

A polarising filter or a neutral density one to cut the brightness down can improve the contrast of surface details, specially filaments.  The solar surface is generally bright enough to swamp the available contrast.     🙂

[Sunshine]

would  variable polarizing filter be even better? 

[Highburymark]

Polarising filters can be a bit hit and miss with solar scopes. With air-spaced etalons like the Coronado you won’t see any effect comparable to narrowing the bandpass (as with a double stack scope), but it can help by controlling brightness. I must say, I’ve never seen any real improvement with polarisers before the eyepieces, but after reading a thread on CN recently, which claimed that by placing two polarisers after the eyepieces, better results can be achieved, I constructed an adapter for my binoviewer eyepieces (see pic). I did see a modest improvement in the surface background, similar to light cloud passing over the Sun. Again - don’t expect anything like double stack-type changes. But to my eyes it offered slightly more contrasty views than polarising before the eyepiece.

[Highburymark]

I think the other thing to say is if filaments and active regions are washed out or even invisible through a single stack scope, no polariser will help. The only answer then is to dig deep and get a second etalon.