Posted: May 20, 2012 11:16 pm
AlohaChris wrote:Any of you Astronomy-savvy types know what type of solar filters are safe? They range from $$ - $$$, I'm wondering if the commercial $50-80 ones are safe for a small Dob?
Baader Planetarium in Germany sell solar filter material by the sheet. You make your own cell. There are also retailers that sell the Baader filter material in pre made full aperture cells. Before using any solar filter, check for damage, pinholing etc. Also make sure that the cell is securely fitted to your scope. A gust of wind blowing it off would be disaster.
You can often get a better view via unfiltered eyepiece projection onto a screen, just be aware that you will get a lot of heat around the focal plane which can be detrimental to your eyepiece - especially if there are any plastic parts. With projection, several people can view at once. Generally a low power 2" eyepiece will deal with the heat better than a 1 1/4 one. Also eyepieces with cemented elements should be avoided as they are likely to be ruined. You should be fine though unless you are talking a large aperture scope (not recommended unless stopped down).
PS. Beware of your finder. It will need its own filter or otherwise securely cap it, or even better remove it. Don't leave your solar scope unattended, especially if there are children around.