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Originally Posted by acropolite
A question on filters and solar observing. We know that the Coronado PST gives superb views of the sun, particularly it's structure and prominences. Given that the PST allows only h alpha wavelengths through, has anyone tried an h aplha EP filter in combination with solar film to see if the same effect occurs. 
Note: Before anyone jumps in, I am not suggesting using the h aplha EP filter without a suitable (baader or 1000oaks film etc) solar filter on the front of the OTA. |
This doesn't work because the bandwidth of the H-Alpha filter is not narrow enough to capture ONLY the H-Alpha line. The bandwidth of a typical H-Alpha filter is easily 200nm or more. You need 0.1nm at most.
There are available (see lumicon.com) H-Alpha filters that cover the front of the scope and provide the correct bandwidth, but they are expensive (~$900US for a filter appropriate for an 8" scope).