What Filters?

[Astrosurf]

I've got a Baader solar filter and wondered what filters I could use to see specific features of the Sun? Being a newb I assume the filter is attached to the webcam nosepiece as usual?

Alexxx

[riklaunim]

In white light (with Baader AstroSolar) you can see only sunspots and granulations. Extra filters like Baader Solar Continuum can just enhance the view.

[Astrosurf]

In white light (with Baader AstroSolar) you can see only sunspots and granulations. Extra filters like Baader Solar Continuum can just enhance the view.

That's a shame. In the third paragraph here it says you can use filters to see different parts of the atmosphere.

First Light Optics - Baader AstroSolar Safety Film ND 5.0

[hunterknox]

Strictly speaking I guess that's true. There is the baader CaK filter but it's quite pricey and not really aimed at visual users.

[Astrosurf]

Strictly speaking I guess that's true. There is the baader CaK filter but it's quite pricey and not really aimed at visual users.

Thanks. I think I'll get some more experience first!

[Mr TamiyaCowboy]

i decided upon a ND filter (moon) to help dull down the brightness for my webcam.

but i also decided on an red'ish filter and a orange'ish filter.

i to have a baader film filter been told color filters can help with contrast and likes.

the color filters i will use with my DSLR setup.

[riklaunim]

For Sun don't use red/infrared with Astrosolar as it will give very low contrast (AstroSolar has such effect). For Moon you use usually those red/infrared filters to limit bad seeing.

[Astrosurf]

Hmmm, I forgot to remove the IR/UV filter in my excitement! I don't think this one turned out too bad though, regardless of drift too.

[Andrew*]

Firstly, Alexxx, your sun pic is very good. Exposure is pretty much spot on. Sharpness needs work. Probably the focus is very slightly off, or the solar film is stretched. It needs to be quite loose to get a really sharp picture. When I stopped using my home-made cardboard filter-holder, and bought a proper metal one, where the film is evenly supported with no tension in any direction, the increase in sharpness was amazing. I could get this result with the cardboard filter, but I would have to re-make it every session!

The statement that you can view different parts of the atmosphere with astrosolar film is as far as I know, either false, or misleading. It's Baader's own blurb, so it's not FLO's fault, but I think they should consider removing it from the description. When you view in continuum, you are viewing the photosphere, which is the surface. I don't believe you can view any part of the atmosphere with AstroSolar film. This can only be done with a dedicated narrow-band solar filter system.

However, it is true that you can use different coloured filters with astrosolar film to enhance different features on teh surface. Baader's solar continuum filter is basically a posh green filter which gives good contrast on faculae (lighter areas associated with active regions, seen near the limb) and granulation. An ordinary #56 or #58 green filter gives a pretty close result. Violet or blue filters also give excellent contrast on faculae.

Red filters give enhanced contrast on small features in the penumbra.

Also, any single colour filter will be helpful to reduce the effects of atmospheric refraction or chromatic abberation.

Saying all that, in my personal experience, contrast with AstroSolar film (when correctly set up) is excellent for viewing all white light features as it is. Supplementary filters offer little significant improvement, to the extent that I don't usually bother with them unless I am doing a particularly thorough observation.

Andrew

[Astrosurf]

That's great info Andrew. Thanks for helping.

The atmospherics were so awful I got tension headache trying to focus! I'm glad it was close though.

The film is loose, but does flap in the wind which doesn't help with focusing. I'm really glad I have this filter though. It's launched me into a new and exciting field! Once I get my hand in I'll buy one from FLO.